Place the chilli, lemon juice, garlic, oil, sugar, salt and pepper in a non-metallic bowl and stir well to combine. Place the fish in a non-metallic bowl and pour over half the chilli mixture. Toss to coat and set aside for 5 minutes. Combine the remaining chilli mixture with the tomato and toss to coat. Heat a large non-stick frying pan over high heat. Cook fish for 2–3 minutes each side or until cooked through. Top tortillas with avocado, lettuce, fish and tomato mixture, roll to enclose and serve with lime. Serves 4.