A molcajete is a Mexican mortar and pestle made from basalt, or volcanic rock. Basalt is porous, so food flavors carry on from one use to the next. Salsa is traditionally made in a molcajete. The ingredients impart more flavorful essential oils in the mashing process. The following is a very general salsa recipe. Feel free to make adjustments to taste.
Line your baking sheet with foil and broil the tomatoes, garlic, jalapeño pepper and chili. If you are using a dried chili, brush it with oil before putting it in the oven. Broil for eight minutes, then flip them over and broil for another eight minutes.
Let the ingredients cool. Peel the tomatoes, garlic, jalapeño pepper and chili. Seed the pepper and chili and cut into smaller chunks.
Add coarse salt, garlic, jalapeño and chili to the bottom of the molcajete. Pound with the pestle until the mixture is pastelike.
One at a time, add tomatoes, then onion and cilantro. You should grind them into a desired texture before adding the next ingredient.
Add lime juice to thin out the mixture. Add additional salt to taste.