This recipe combines all the goodness of homemade tuna salad with the health benefits of avocado, as a substitute for mayonnaise.
Cut the avocado in half and scoop the middle of both avocado halves into a bowl, leaving a shell of avocado flesh about 1/4 inch thick on each half.
Add lemon juice and onion to the avocado in the bowl and mash together. Add tuna, salt, and pepper, and stir to combine. Taste and adjust if needed.
Fill avocado shells with tuna salad and serve.