In a large bowl, place the avocados, tomatoes, onion, cilantro, serrano, lemon juice, and salt, to taste. Stir gently until well combined. Transfer to a serving bowl and serve.
To keep the guacamole from turning brown, press a pit from one of the avocados into the center of the dish. Remove it before serving.
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.