In Mexico, salsas are typically made with ingredients roasted on a clay comal, or griddle. A cast-iron skillet is a good substitute. When whole chile peppers, unpeeled garlic cloves, tomatoes, and tomatillos are dry-roasted, they brown as they cook and develop the toasty overtones that create deep flavors in the salsa. Another traditional tool is the molcajete y tejolote, a rough stone mortar and pestle used to mash and blend the salsa.
Cooks' Note
Green tomatillo salsa is very good with diced fresh avocado added at the end; you may need to add a little water to thin the salsa.
