Courtesy of Chef Edgar Gutierrez of Tres Carnales.
Combine the onions , vinegar, lime juice, salt and pepper and set aside for at least 3 hours.
Peel and seed the avocados and mash. Reserve pits (the avocado pit will keep the guacamole from turning brown).
Chop the jalapeño and combine with tomatoes, cilantro, garlic powder, marinated onion.
Combine all ingredients in a large bowl including pits. Mix thoroughly.
Serve immediately with corn chips.