Step 1

Slice the onions very thinly and put them in a microwaveable container. Add the salt and sugar. Cover everything with 1 part water to 2 parts vinegar.

Step 2

Microwave for 1 minute, stir, and microwave for another minute. Cool, then refrigerate overnight (if you have time).

Step 3

Heat the oven to 350° F. Season the fish with salt, then the cumin and chile. Lay the fish in a baking dish, and sprinkle with the olive oil.

Step 4

Meanwhile, set out the pickled onions. Slice the avocado and put it in a bowl (I like to squeeze a little lime juice over it so it doesn’t brown). Wash and dry the cilantro and pile it on your counter. Do the same with the lime wedges.

Step 5

When the oven is hot, bake the fish until just cooked through, about 10 minutes. While the fish roasts, place a large skillet over medium high heat. Add as many tortillas as you can – probably just 2 – and toast for a minute or two on each side, just enough to warm through and leave a light toasting mark; be careful not to let them dry out. Keep the warm tortillas piled under a clean tea towel.

Step 6

When the fish is ready, serve it with the warm tortillas and all the fixins, and let everyone have at it, making their own dream fish tacos.