In a large bowl, add the shrimp, chili powder, paprika, onion powder, cumin, garlic powder, and salt and pepper. Set aside.: The mixture will smell warmly spiced and lightly dusty from the dried seasonings; that aroma tells you the flavor base is concentrated and ready. Seasoning the shrimp ahead allows the spices to cling, which is why I always mix everything in a roomy bowl so each piece gets coated. A common mistake is crowding the bowl and leaving clumps of seasoning on some shrimp , so toss gently and use your hands if needed to rub the spices evenly. If the spice feels too intense, pause and adjust with a pinch more salt to balance. When you set it aside, the coated shrimp will glisten slightly from natural moisture and the seasonings will darken a bit as they marry with the surface of the seafood.
In a medium-sized skillet over medium high heat, add 1 tablespoon olive oil and the sliced bell peppers and onion. Saute until tender about 5-7 minutes. Slide the cooked vegetables to the side of the skillet.: You should hear a gentle sizzle as the vegetables hit the oil, and the skillet will start to smell sweet and caramelized after a few minutes. The goal is softened, slightly blistered peppers with translucent edges on the onion , that combination bringing a sweet aroma that complements the spices. Use a spatula to move pieces and watch for browned bits, which add flavor; if the pan smokes a lot, lower the heat slightly to avoid bitterness. One frequent error is over stirring which prevents the peppers from getting any char, so let them sit undisturbed for short intervals to develop color. When they are tender, push them to the side to create space for searing the shrimp , maintaining that pan fond to flavor the seafood.
Add the remaining 1 tablespoon olive oil and add the seasoned shrimp. Cook for 2-3 minutes or until pink.: The sound will shift to a lively sizzle as the shrimp hit the hotter oil, and you will notice steam rising and edges beginning to brown. The visual cue is critical, watch for the flesh to turn opaque and pink with a slightly curled shape; that indicates doneness. This quick, high heat sear locks in juices and produces those toasty blackened bits that carry the seasoning's flavor. Avoid overcooking, which makes shrimp rubbery; remove them the moment they are fully opaque. A common misstep is cooking too many shrimp at once, which lowers the pan temperature and causes steaming rather than searing, so cook in batches if needed. After searing, mingle the shrimp briefly with the peppers to marry the flavors before serving.
Serve in tortillas with optional toppings.: At this point you will notice the air filled with smoky spice and the skillet studded with browned bits that promise flavor in every bite. Place warm tortillas on a platter and spoon the shrimp and vegetables into them, adding chopped avocado , cilantro, and a dollop of sour cream if you like. The contrast of cool garnishes against spicy shrimp brightens each mouthful and rounds the dish. One tip is to warm the tortillas briefly in a dry pan or wrapped in a towel to keep them pliable, avoiding cracked shells. Be mindful not to overload the tortillas, which can make them hard to eat; portion evenly so each one holds together and the textures stay balanced.