2 avocados, peeled and stoned
1 medium onion, chopped
2 green chiles, seeded and chopped
1 tablespoon lemon juice
1 teaspoon salt
Freshly ground black pepper to taste
4 to 8 tablespoons mayonnaise, to taste
2 medium tomatoes, skinned and finely chopped
Tortilla chips, to serve

Place the avocados, onion, chiles, lemon juice, salt and pepper in a food processor or blender and process until creamy. Add the mayonnaise and process briefly, then turn the mixture into a bowl and stir in the chopped tomatoes. Cover and chill.

Serve with tortilla chips.