Directions

1. Heat 2 tablespoons of the olive oil in a large, heavy skillet over medium-high heat. Add the onion, pepper and a generous pinch of salt, stirring to coat the vegetables in the oil. As soon as the onions start to brown a little around the edges, turn down the heat to medium low and cook, stirring occasionally, until the onions and peppers are tender but still have a bit of a bite, about 5 more minutes. Taste and add more salt if necessary, as well as a few grinds of pepper. Set aside.
2. Heat a grill so that it is quite hot, but not blazing. While it’s heating, peel and cut the avocados into thin slices and arrange them with the cilantro and lime wedges on a plate. Rub the fish all over with the remaining 2 tablespoons of olive oil and season generously with salt and pepper. When the grill is hot, gently lay the fish on it and cook, without fiddling with it, for 2 to 4 minutes per side, depending on how thick the fillets are. You want it cooked through, but not at all dry. Gently remove the fish to a plate and keep warm. (If you’re not grilling, just cook the fish in a non-stick pan over medium-high heat the same way.)
3. Wrap the tortillas in a stack in aluminum foil and seal. Put the foil packet of tortillas on the grill and cover for a few minutes, until they are warm. Alternatively, you can heat the tortillas a couple at a time right on the grill, using tongs to flip them after about 10 seconds.
4. To assemble a taco, break the fish into large chunks with a fork. Take a warm tortilla and put several pieces of fish in a line down the center. Top with a forkful of the onions and peppers, a few slices of avocado and a pinch of cilantro leaves. Add a generous spritz of lime juice and some salsa if you like. Roll and eat. Leave it up to your guests to make their own, and remind them that if they get messy in the process, they’re doing it right!