Finely chop the onion. Slit, deseed, rinse, dry and finely chop the green chilli. Peel, deseed and chop the tomato.

Peel and stone the avocados. Mash to a chunky consistency in a bowl. Add the lemon juice, onion, garlic and pepper. Stir in the chopped tomato, then transfer the dip to a serving bowl or four individual bowls.

Chill for at least 15 minutes. Serve with taco chips, salted crisps, or vegetable crudites.