Pit the avocadoes and roughly mash them in a mixing bowl using a fork or a potato masher, don't overdo it. It's nice to leave some chunks. When you add the rest of the ingredients, they will naturally become more of a cream.
Mix the chopped tomatoes, onion, garlic, cilantro, lemon juice, and jalapeno pepper into mashed avocado until well combined; season with salt and extra-virgin olive oil (optional).
Leave the avocado seed inside the guacamole to prevent it from darkening. Serve with totopos (nachos).
