Prepare ingredients: Peel and devein 1 ½ pounds of jumbo shrimp. Thinly slice 1 yellow onion and 2 bell peppers (preferably red and yellow) into strips to streamline cooking.

Make fajita seasoning: In a small bowl, mix ½ tablespoon chili powder, ½ tablespoon ground cumin, 1 teaspoon garlic powder, ½ teaspoon smoked paprika, ½ teaspoon dried oregano, ½ teaspoon salt, ¼ teaspoon black pepper, and optional ¼ teaspoon onion powder and ½ teaspoon crushed red pepper flakes.

Marinate shrimp: In a large bowl, toss shrimp with 2 tablespoons olive oil, juice from half a lime, and half of the fajita seasoning. Let marinate for up to 15 minutes, avoiding longer to prevent mushy shrimp.

Cook vegetables: Heat remaining 2 tablespoons olive oil in a large skillet over medium heat. Sauté sliced onions and bell peppers for 4 to 5 minutes until softened and onions start to caramelize. Transfer veggies to a plate.

Cook shrimp: Using the same skillet, cook shrimp 2 to 3 minutes per side until pink and opaque.

Combine and finish: Return peppers and onions to the skillet, toss with shrimp, and squeeze juice from the remaining half lime over the mixture.

Serve: Warm 8 to 12 flour tortillas. Serve the shrimp and vegetables hot with your choice of toppings such as guacamole, sour cream, salsa, chopped cilantro, and lime wedges.