Cut the avocados into quarters.

Remove the seeds and peel the avocado quarters.

Place the avocado flesh in a mixing bowl.

Mash the avocados with a potato masher or fork until chunky.

Add the chopped fresh cilantro, diced red onion, and lemon juice to the bowl.

Season with salt and freshly ground black pepper.

Combine all ingredients with a fork until well mixed.

Mound the guacamole on a bed of shredded lettuce.

Garnish with sliced tomatoes.

Sprinkle with additional freshly ground black pepper.

Serve immediately.