Who knew jalapeno's were the secret ingredient in terrific guacamole. I'll never leave them out now that I know. You can make this ahead and wrap it in plastic for up to 24 hours (good luck with that, I can't keep my hands off it once it's made). Just make sure the plastic wrap is touching the surface of the guacamole and bring to room temperature and season with additional fresh lime juice and salt before serving. Recipe courtesy of The America's Test Kitchen Family Cookbook.