Cut the avocados in half, remove the pits, and scoop the avocado into a large bowl. Mash the avocado with a potato masher or fork.
Add the tomatoes, onion, jalapeño, cilantro, lime juice, salt, and pepper. Mix until well combined.
Taste and adjust the seasonings as needed.
Notes
Scoop the seeds out of the Roma tomatoes before dicing so the guacamole doesn't get too watery.Remove the seeds and ribs from the jalapeño for a milder guacamole.