If using, rinse cilantro. Pluck leaves from stems. Tear into small pieces.
Mince onion and garlic. Dice tomatoes into ¼ inch pieces.
Rinse lime and cut in half. In a medium bowl, squeeze juice from each half. Discard seeds.
Cut avocados in half. Remove pits. Using a large spoon, scoop out flesh and add to bowl with juice.
Add salt to avocado. If using cumin, add now. Mash well with a fork.
Add onion, garlic, and tomatoes to avocado mixture. If using cilantro, add now. Stir well.
Serve as a dip with homemade tortilla chips, whole grain pita wedges, or fresh veggies. Add ¼ cup serving of carrot sticks, broccoli florets, celery sticks, jicama sticks, or turnip sticks to have a full veggie component for snack.
The lime keeps the avocados from turning brown. Keep in a sealed container in the refrigerator to maintain look and taste for a couple of days.