Slice the avocados in half, remove the pits, and scoop the flesh into a medium mixing bowl.
Add the lime juice immediately to prevent browning and to add brightness.
Using a fork or potato masher, mash the avocados until creamy with some small chunks remaining. The texture should not be completely smooth.
Stir in the onion, tomato, jalapeño, cilantro, salt, pepper, and garlic (if using). Mix gently so the avocados don’t become over-mashed.
Taste and adjust seasonings. Add more lime juice or salt as needed.
Serve immediately with tortilla chips, or cover tightly with plastic wrap pressed directly against the surface to keep fresh until ready to enjoy.