Peel and chop the avocados into 1/2" pieces. Lightly mash with a fork, leaving plenty of chunks. Add the onion, avocado, lime juice, salt, and pepper.
Stir to combine and taste. Adjust the lime, salt, and pepper as needed. Serve immediately or cover tightly and refrigerate until ready to serve. Enjoy!
If you don't plan to serve the guacamole immediately after making it, save an avocado pit. After the guacamole is made, place the pit in the container with the guacamole. This will help slow down the browning of the avocado. Remove the pit before serving.