Cut up the avocados and place in a large glass bowl, toss with 2 or 3 tablespoons of lime juice. Set aside while you chop up the other ingredients. The more lime juice you use, the longer the guacamole will keep without turning brown, but adjust to your taste if you don’t like it too sour. (I love sour!)
Finely dice the onion. Seed and dice the tomatoes. Seed and finely dice the jalapeno. Mince the garlic and cilantro leaves. Put everything in another bowl and set aside.
Add salt, cumin and cayenne pepper to the avocado, mash with a potato masher. Fold in the rest of the ingredients.
Taste and add more salt, spices and lime juice to your liking.