In a large skillet, heat over medium heat and add diced bacon. Cook for about 8–10 minutes until crispy and browned. Transfer bacon to a paper towel-lined plate to drain excess grease.

Bring a large pot of salted water to a rolling boil. Add frozen cheese tortellini and cook according to package instructions, about 5–7 minutes until al dente. Drain and rinse under cold water.

In a large mixing bowl, combine mayonnaise, red wine vinegar, and pinch of salt. Add oregano, Italian seasoning, garlic powder, and red pepper flakes. Whisk until smooth.

Add cooled tortellini, cooked bacon, sliced pepperoncini, halved cherry tomatoes, and chopped red onion to the dressing. Sprinkle in grated Parmesan cheese and gently toss until thoroughly coated.

Cover the bowl with plastic wrap or a lid and refrigerate for at least 2 hours to allow flavors to meld.

Before serving, gently stir the salad and adjust seasoning with salt or vinegar if needed. Serve chilled.