Cut the avocados into quarters and remove the seeds. Peel the fruits and put them in a mixing bowl. Mash them with a potato masher or fork until chunky. Add the cilantro, onion, chiles, lime juice, salt, and pepper and mix with a fork until all the ingredients are evenly dispersed. Mound the guacamole on a bed of shredded lettuce and garnish with the sliced tomatoes on the side.
nutrition information (per serving):