Name: Easy Slow-Roasted Tuna Recipe with Harissa & Olives Bliss
Prep time: 15 min
Cook time: 20 min
Total time: 45 min
Ingredients: 1 pound Albacore Tuna (cut into 1x1.5-inch chunks); 1 teaspoon Fine Sea Salt; 1 teaspoon Freshly Ground Black Pepper; 2 tablespoons Harissa (can substitute with Aleppo pepper or red chile flakes); 1 cup Sliced Pitted Olives (black or green); 3 cloves Garlic (coarsely chopped); 1 leaf Bay Leaf (fresh); 2 sprigs Rosemary or Thyme (choose according to preference); 2 tablespoons Extra-Virgin Olive Oil; 1 teaspoon Flaky Sea Salt (for garnish); 1 lemon Lemon Wedges (for serving)

On a lazy Sunday afternoon, I found myself yearning for something special yet simple—a dish that would transport me to sun-kissed Mediterranean shores without an all-day commitment. Enter my Easy Slow-Roasted Tuna Recipe with Harissa & Olives, a delightful harmonization of flavors that captures the warmth and vibrancy of the region. Imagine tender chunks of albacore tuna, gently kissed by a spicy harissa glaze and surrounded by briny olives and fresh herbs; it’s a meal that not only dazzles but also checks the boxes for a low-carb and gluten-free option. Whether you’re hosting a dinner party or simply treating yourself to a comforting meal, this recipe is a quick prep that promises to impress. Curious about the best way to serve it? Let’s dive in!

Why Choose Slow-Roasted Tuna?

Simplicity: This recipe requires minimal prep time, making it perfect for busy weeknights or spontaneous gatherings.

Mediterranean Bliss: Experience vibrant flavors from harissa and olives that will transport your senses to a sunny locale.

Healthy Indulgence: Low-carb and gluten-free, it’s a guilt-free meal that fits seamlessly into any healthy eating plan.

Versatile Pairing: Enjoy this tuna with sautéed greens or on a bed of quinoa for a filling, balanced dish. For more delicious pairings, check out my Karaage Chicken Umami or Sticky Chicken Bowls.

Crowd-Pleaser: This stunning dish impresses family and friends alike, making it a go-to for gatherings.

Meal Prep Friendly: Cook in advance and savor the leftovers in salads or sandwiches for hassle-free lunches!

Easy Slow-Roasted Tuna Ingredients

For the Tuna
• Albacore Tuna – The star ingredient for this dish, yielding a tender and moist texture. Ensure it’s cut into 1×1.5-inch chunks for even cooking.
• Fine Sea Salt – Enhances the flavor of the tuna beautifully.
• Freshly Ground Black Pepper – Adds depth and warmth to every bite.
• Harissa – This spicy chili paste is essential for that Mediterranean flair; substitute with Aleppo pepper or red chile flakes if needed.

For the Aromatics
• Sliced Pitted Olives – Choose either black or green for a briny burst of flavor that perfectly complements the tuna.
• Garlic – Coarsely chopped to infuse the dish with a wonderful aroma.
• Bay Leaf – Fresh is best for that earthy flavor magic.
• Rosemary or Thyme – Fresh herbs that enhance the overall essence; choose rosemary for a punchier taste or thyme for subtlety.

For Cooking
• Extra-Virgin Olive Oil – Essential for a flavorful and moist cooking environment.
• Flaky Sea Salt – Perfect for garnishing and elevating the final presentation.
• Lemon Wedges – A must for serving, adding a refreshing acidity that lifts the dish.

Step‑by‑Step Instructions for Easy Slow-Roasted Tuna Recipe with Harissa & Olives

Step 1: Preheat the Oven
Begin by preheating your oven to 350°F (175°C). This temperature creates the perfect environment for the tuna to slowly roast, allowing the flavors of harissa and olives to meld beautifully. Make sure your oven rack is positioned in the middle for even cooking, and have an oven-safe dish ready for the next steps.

Step 2: Season the Tuna
While the oven is heating up, take your albacore tuna chunks and place them in a mixing bowl. Generously rub the tuna pieces with fine sea salt, freshly ground black pepper, and a rich layer of harissa. This seasoning ensures that the tuna absorbs all those robust Mediterranean flavors, setting a delicious foundation for your Easy Slow-Roasted Tuna.

Step 3: Arrange in the Dish
Next, transfer the seasoned tuna chunks into your oven-safe dish, arranging them snugly together. This packing not only helps retain moisture but also allows the harissa coating to flavor each piece thoroughly. Visualize the tuna forming a beautiful cluster, ready for the aromatic companions that will join them in the dish.

Step 4: Add Aromatics
Surround the tuna with sliced pitted olives, coarsely chopped garlic, a fresh bay leaf, and your choice of rosemary or thyme. These aromatics will infuse the dish with delightful flavors as it bakes. Drizzle extra-virgin olive oil generously over the tuna and aromatics, ensuring everything is well-coated, which will help prevent drying out during roasting.

Step 5: Bake the Tuna
Cover the dish tightly with aluminum foil and place it in the preheated oven. Bake for about 12-20 minutes, depending on thickness, until the tuna is just slightly underdone; it should be firm to the touch but still tender. Check for doneness by gently pressing the fish; it will continue cooking outside the oven, so aim for a rosy interior.

Step 6: Let It Rest
Once the tuna is finished baking, take it out of the oven and allow it to rest, covered, in the pan for about 10 minutes. This step is crucial as it helps the flavors settle and the moisture redistribute throughout. During this time, the harissa glaze will thicken slightly, enhancing its richness.

Step 7: Serve the Dish
When ready to serve, gently transfer the tuna to a beautiful platter. Garnish with flaky sea salt for a touch of elegance. Accompany your Easy Slow-Roasted Tuna with lemon wedges on the side, allowing guests to add a bright, zesty finish that elevates the dish even further. Enjoy warm or at room temperature for a delightful Mediterranean meal!

Expert Tips for Easy Slow-Roasted Tuna

Avoid Overcooking: Keep a close eye on the tuna while baking; slightly underdone is preferable to ensure a moist texture.
Use Fresh Ingredients: Utilize fresh herbs and good-quality olives for the best flavor in your Easy Slow-Roasted Tuna recipe with harissa & olives.
Opt for Snug Arrangement: Arrange the tuna pieces close together in the dish to retain moisture and maximize flavor absorption during roasting.
Metal vs. Ceramic: If using metal pans, reduce baking time slightly, as they conduct heat more efficiently than ceramic or glass dishes.
Enhance Presentation: Don’t forget to garnish with flaky sea salt and serve with lemon wedges for a beautiful and flavorful finish that invites everyone to dig in!

How to Store and Freeze Easy Slow-Roasted Tuna

Fridge: Store leftover Easy Slow-Roasted Tuna in an airtight container for up to 3 days; it’s perfect for adding to salads or sandwiches.

Freezer: For longer storage, freeze the tuna in a freezer-safe bag, removing as much air as possible. It should maintain quality for up to 2 months.

Reheating: Thaw frozen tuna overnight in the fridge and reheat gently in the oven at 300°F (150°C) until warmed through, avoiding overcooking.

Wrap: If storing individual portions, tightly wrap each piece in plastic wrap before placing them in a container to preserve flavor and moisture.

Easy Slow-Roasted Tuna Variations

Feel free to make this dish your own with a few simple tweaks that will tantalize your taste buds!

Spice Level Boost: Add diced jalapeños or a sprinkle of crushed red pepper flakes for a fiery kick that’s sure to ignite your palate.
Herb Swap: Substitute fresh basil or parsley for rosemary or thyme to create a fresh twist on the classic Mediterranean flavor profile. Basil adds a sweetness that beautifully complements the tuna.
Different Fish: Swap albacore for salmon or swordfish to suit your preferences; both options will retain the moist texture yet offer their unique flavors.
Olive Variety: Experiment with different types of olives, such as Kalamata or Castelvetrano, to introduce varied briny notes that elevate each bite.
Citrus Zest: Add lemon or orange zest to the harissa mixture for a bright, citrusy aroma that lightens the dish perfectly. The zest brings a delightful freshness that makes each mouthful pop.
Serve Over Grains: Instead of serving on a bed of greens, try a base of couscous or farro for a hearty, satisfying meal. This choice adds texture and pairs wonderfully with tuna.
Add Vegetables: Toss in some halved cherry tomatoes or artichoke hearts with the olives for a colorful, flavorful medley that enhances the overall dish.

For more inspiration on what to pair this dish with, check out my delicious Dessert Cups Black. If you prefer a heartier meal, my Beef Soup Kharcho is an ideal option too!

What to Serve with Slow-Roasted Tuna with Harissa and Olives

Elevate your culinary experience with delightful accompaniments that harmonize beautifully with this Mediterranean treasure.

Quinoa Salad: A light and fluffy quinoa salad adds a nutty flavor and chewy texture to complement the tender tuna.
Sautéed Spinach: Bright, sautéed spinach adds a fresh, earthy note that balances the richness of the tuna, creating a vibrant plate.
Garlic Roasted Cauliflower: Nutty and caramelized garlic roasted cauliflower provides a delightful crunch and a slightly sweet flavor profile to contrast the briny olives.
Mediterranean Couscous: Fluffy couscous mixed with cherry tomatoes and herbs introduces a playful texture and bursts of flavor that enhance the tuna dish.
Green Bean Amandine: Crisp-tender green beans garnished with toasted almonds offer a satisfying crunch and a subtle nutty flavor, enhancing the overall meal experience.
Citrus Herb Salad: A fresh salad tossed with seasonal citrus and fragrant herbs offers a refreshing acidity to balance the depth of the harissa.
Chilled Rosé: Enjoy a glass of crisp, chilled rosé wine; its fruity notes and vibrant acidity perfectly match the Mediterranean spices and flavors of the dish.

Make Ahead Options

These Easy Slow-Roasted Tuna with Harissa and Olives are perfect for busy home cooks looking to save time during the week! You can season the tuna with salt, pepper, and harissa up to 24 hours in advance, allowing those flavors to deeply penetrate the fish. Additionally, you can chop the aromatics (garlic, olives, herbs) and store them in the refrigerator for up to 3 days before baking. To maintain quality, ensure all ingredients are tightly covered to prevent drying out. When you’re ready to serve, simply gather your prepped components, arrange them in the baking dish, and roast according to the original recipe instructions for a delightful meal that tastes just as delicious as if you made it fresh!

Easy Slow-Roasted Tuna with Harissa and Olives Recipe FAQs

How do I choose the best tuna?
Absolutely! For this recipe, look for fresh albacore tuna that has a bright, firm texture and a clean sea smell. If you notice any dark spots or an off-putting odor, it’s best to steer clear. Aim for chunks that are cut into 1×1.5-inch pieces to ensure even cooking—this way, you’ll have a delicate and moist outcome.

How should I store leftovers?
Very! After enjoying your meal, store any leftover Easy Slow-Roasted Tuna in an airtight container in the fridge. It will stay fresh for up to 3 days. This makes it a fantastic addition to salads or sandwiches—a quick, tasty lunch that will keep you satisfied!

Can I freeze the slow-roasted tuna?
Certainly! Freezing is a wonderful option if you want to keep your Easy Slow-Roasted Tuna longer. To do this, allow it to cool completely, and then place it in a freezer-safe bag, making sure to squeeze out as much air as possible. It can be frozen for up to 2 months. When you’re ready to enjoy it, simply thaw in the fridge overnight and reheat gently in the oven at 300°F (150°C) for even warming.

What should I do if my tuna turns out dry?
If you find your tuna a bit on the dry side, don’t worry; you can still salvage it! Adding a drizzle of extra-virgin olive oil or a squeeze of fresh lemon juice can help reintroduce moisture and elevate the flavor. Also, in the future, keep in mind to avoid overbaking it—tuna is best enjoyed slightly underdone, so watch your cooking time closely!

Is this recipe suitable for those with dietary restrictions?
Absolutely! This Easy Slow-Roasted Tuna with Harissa and Olives is both low-carb and gluten-free, making it a fantastic choice for various dietary needs. However, if you’re serving it to those with potential allergies, ensure that the harissa and olives you use are free from cross-contamination. For pet owners, remember that tuna can be a treat but should not be given in excess to pets.

What are the best sides to serve with this dish?
So many delightful options! This tuna pairs beautifully with sautéed kale or spinach for a nutritious boost, or you can serve it over a fluffy bed of quinoa or farro for a more filling meal. If you’re looking for contrast, a refreshing salad on the side could also shine alongside the robust flavors of the tuna.