1. To remove excess salt from the fish, bring the fish to a boil in a large pot of water. Drain the water, and repeat the process. Drain the fish, flake, and press liquid out.
2. In a large skillet, sauté oil, onions, tomatoes, and peppers for 2 minutes. Mix in flaked saltfish, lemon juice, and hot pepper. Cook mixture at low heat until the moisture has almost completely evaporated.
3. Pile the mixture into the center of a serving dish, and arrange lettuce and avocado around it.