Slice the avocados in half, remove the pit, and scoop the flesh into a large mixing bowl.
Use a fork or potato masher to gently mash the avocado to your preferred level of chunkiness.
Add the diced onion, tomatoes, cilantro, jalapeno, garlic, lime juice, and sea salt to the bowl.
Gently fold the ingredients together until well combined, being careful not to overmix.
Taste and adjust seasoning with additional salt or lime juice if desired. Serve immediately.
Notes
To store leftovers and prevent browning, place the guacamole in an airtight container, smooth the top, and pour a thin layer of cold water over the surface before refrigerating. Drain the water before serving.