Wash the lemon, tomato and herbs, avocado, egg and onion.
Cut the egg, avocado and tomato into medium cubes. Chop the onion into thin feathers, chop the garlic finely.
Add tuna fillets and greens to the chopped products. Add salt and a little sugar (if the tomato is sweet, no sugar is required).
Sprinkle the salad with lemon juice and season with oil. Pepper as desired.