Avocado, Tomato, Cucumber salad

Ingredients: 4 cups avocados, diced medium 2 cups grape tomatoes or 2 cups cherry tomatoes 2 cups cucumbers, peeled and diced medium 1 cup red onion, diced small 4 tablespoons fresh cilantro, chopped 2 teaspoons fresh garlic, minced 2 tablespoons lime juice 1/4 cup olive oil salt fresh black pepper bibb lettuce, as desired