In a mixing bowl whisk together vegetable oil, lime juice, garlic, chili powder, cumin, paprika, cayenne pepper, and season with salt and pepper to taste. This mixture should smell fragrant and flavorful. Make sure all the spices are well combined, creating a delicious marinade.
Next, place the fish into a dish or a gallon-sized resealable bag. Pour the marinade over the fish, ensuring it’s evenly coated. If using a bag, seal it and gently move the bag around to ensure the fish is well-marinated. Let it marinate for about 20 minutes, but no longer than 30 minutes, as the acidity of the lime juice can start to cook the fish.
Preheat your grill to medium-high heat. Once hot, brush the grill grates with a bit of oil to prevent sticking. Place the marinated fish directly on the grill. Grill for about 3 minutes per side, or until the fish is cooked through and flakes easily with a fork. The outside should have lovely grill marks, giving it a smoky flavor.
If you prefer baking, preheat your oven to 400 degrees. Line a baking sheet with parchment paper or lightly spray it with non-stick cooking spray. Place the fish on the prepared baking sheet and bake for about 10 to 15 minutes, until the fish is opaque and flakes easily with a fork. The smell of the fish baking will fill your kitchen with a wonderful aroma.
For a stovetop method, heat a 12-inch non-stick skillet over medium-high heat and drizzle lightly with vegetable oil. Remove the fish from the marinade and gently place it in the skillet. Cook for about 3 to 4 minutes per side until golden brown and cooked through. Keep an eye on it, as cooking times may vary depending on the thickness of the fish.
While the fish is cooking, prepare the sauce by whisking together sour cream, mayonnaise, lime juice, and garlic powder in a small bowl. This sauce will add creaminess and a delightful tang to your tacos. Season with salt to taste.
Once the fish is cooked, break it into large pieces. It should be flaky and tender. Warm the corn tortillas in a dry skillet or microwave until pliable.
To assemble your Fish Tacos, take a warm tortilla and layer it with pieces of the cooked fish. Top it generously with shredded cabbage, sliced avocado, chopped cilantro, and sprinkle with Cotija cheese if using.
Drizzle the prepared sauce over the top and finish with a squeeze of fresh lime juice to brighten up the flavors. Enjoy your creation while it’s fresh!
