At the Rosa Mexicano restaurants in New York City, guacamole is prepared tableside in a traditional molcajete. The result is one of the best guacamoles we've ever had—here's how they do it. Get the recipe »
Grind 1 tbsp. of the onions, 1 tbsp. of the cilantro, jalapeño, and salt together in a molcajete until all the ingredients are well ground. (Alternatively, use a fork to mash the ingredients to a paste in a wide bowl.)
Cut avocados (about 8 ounces each) in half. Twist the halves to separate them and remove the pit with the tip of the knife. Place an avocado half, cut side up, in your palm and make 3 or 4 evenly spaced lengthwise cuts through its flesh down to the skin, without cutting through the skin. Make 4 crosswise cuts in the same fashion.
Scoop the diced avocado flesh into the molcajete. Repeat with remaining avocado halves. Gently fold the avocado into the chile-onion paste, keeping the avocado pieces fairly intact.