For the mango-avocado salsa:
1. Remove and discard the pit and skin from the avocado and rub the flesh of the avocado with some of the lime juice to prevent it from discoloring.
2. Chop the avocado and toss it with the remaining lime juice, mango, red pepper and scallions. (This can be made in advance and stored in the refrigerator for up to 1 day.)
For the fish:
3. Preheat the grill.
4. Brush the fillets with oil and season generously with salt and pepper.
5. Grill the fillets on both sides until just cooked through, about 5 minutes per side. (Thin fillets take less time, thicker fillets take more.) Cool slightly and cut into 1-inch pieces.
6. Meanwhile, separate the tortillas into 2 stacks, wrap them in foil and warm them on the grill while the salmon is cooking.
To serve the tacos: 7. Fill the tortillas with fish, lettuce, tomatoes and mango-avocado salsa. Serve 2 tacos per person with lime wedges on the side.Serving Size: 2 tacos with salsa