1-First step: get the oven and pan ready

Start by preheating your oven to 425°F. Line a baking sheet with parchment paper or foil so cleanup stays easy. This temperature is the sweet spot for baked fish tacos because it cooks the fish quickly while helping the outside get a little texture.

While the oven heats, check that your fish filets are fully thawed if they were frozen. The easiest method is to thaw them in the fridge overnight. If you need them sooner, place the sealed bag in cool water for about 30 minutes. Once thawed, pat the filets dry very well with paper towels. Dry fish helps the oil and spices stick better.

2-Second step: season the fish

Place the fish on a plate or cutting board and drizzle it with 1 tablespoon extra virgin olive oil. Rub the oil over all sides of the filets so every piece gets coated. You can also use avocado oil if that is what you have on hand.

Next, mix the spice blend in a small bowl if you have not already. Combine the 1 tablespoon chili powder, 1 teaspoon ground cumin, 1 teaspoon garlic powder, 1/2 teaspoon paprika, 1/4 teaspoon cayenne pepper, 1/4 teaspoon onion powder, 1/4 teaspoon dried oregano, and 1/4 teaspoon salt. Sprinkle the seasoning evenly over all sides of the fish. Do not be shy here. A well-seasoned filet makes the whole taco taste better.

3-Third step: bake the fish

Move the seasoned fish filets to the lined baking sheet. Make sure they are in a single layer and not stacked on top of each other. Bake for 12 to 15 minutes, depending on the thickness of the fish. A good rule is about 10 minutes per inch of thickness.

The fish is done when it looks opaque, flakes easily with a fork, and reaches an internal temperature of 140°F to 145°F at the thickest part. If you are using a meat thermometer, insert it into the thickest section for the best reading. For many home cooks, 140°F is the target that gives tender, juicy fish without drying it out.

If the filets are thick, they may need the full 15 minutes. Thin filets may finish a little sooner. It is better to check early than to overcook them, since overbaked fish can get dry fast.

4-Fourth step: warm the tortillas and prep the toppings

While the fish bakes, warm the 8 small white corn tortillas. You can heat them in a dry skillet for a few seconds per side, wrap them in foil and place them in the oven for the last few minutes, or warm them in the microwave under a damp paper towel. Warm tortillas are softer, easier to fold, and taste much better than cold ones.

Now prep the toppings. Slice the 1 large ripe avocado, dice the 1 medium Roma tomato, dice the 1/3 cup purple onion, chop the 1/4 cup cilantro, crumble the 1/4 cup cotija cheese, and cut the 2 limes into wedges. Having everything ready before the fish comes out keeps dinner moving smoothly.

5-Fifth step: flake the fish and build the tacos

When the fish is ready, remove it from the oven and let it rest for 2 to 3 minutes. Then break it into large flakes using a fork. Try to keep the pieces a bit chunky so the tacos have a nice texture. This also helps the fish stay juicy.

Fill each warm tortilla with a portion of fish, then top with avocado, tomato, onion, cilantro, and cotija cheese. Finish with a squeeze of fresh lime. The lime juice lifts all the flavors and adds the bright, fresh taste that makes fish tacos so good.

6-Final step: serve right away

Serve the tacos while the tortillas are warm and the fish is still hot. If you want to make the meal feel a little fuller, add a side of rice, beans, or a simple slaw. These tacos are best enjoyed fresh, right after assembling.