- Cut the tuna into cubes and toss in the taco seasoning. Set aside.
- In a mixing bowl, toss together the tomato, avocado, chopped red onion, coriander, and shallots. Dress with a squeeze of lemon juice, salt and pepper to taste.
- In a non-stick pan, heat 2 tablespoons of coconut oil. Gently and lightly stir-fry the sliced onion, capsicums and tuna until just cooked. Cool slightly and season with salt and pepper to taste.
- Place the cooked mixture in the lettuce cup.
- Top with the avocado and tomato salsa and serve with a wedge of lemon.