Pat shrimp dry, season with salt and pepper. Heat olive oil in a skillet over medium-high heat. Cook shrimp until pink and opaque, 2-3 minutes per side, then set aside.

In the same skillet, reduce heat, add butter and minced garlic. Sauté for 30 seconds until fragrant.

Add orzo and 2 cups of water to the skillet. Bring to a boil, then simmer for 8-10 minutes until al dente.

Return shrimp to skillet, add spinach and reserved pasta water. Sauté until spinach wilts, about 2-3 minutes.

Zest and juice lemon over the skillet, season with salt, pepper, and red pepper flakes. Stir and serve.