Mexican Roasting Methods
Mexican salsas, soups, and stews owe some of their deep, layered flavor to roasting. Tomatoes, tomatillos, chiles, onions, and garlic are frequently roasted before use to caramelize their sugars and intensify their taste.
To roast tomatoes and tomatillos: Roast on a foil-lined griddle or on a foil-lined baking sheet under a broiler or salamander. Cook, turning often, until the skin blackens and blisters and the flesh softens. Remove the skin.
To roast dried chiles: Remove stems and seeds. Toast the chiles on a moderately hot ungreased griddle, pressing on them with tongs, until they blister a little, color slightly, and release their aroma. Take care not to burn them or they will have an acrid taste.
To roast fresh chiles: Char on an ungreased griddle, over an open flame, or under a broiler until blistered and blackened. Peel.
To roast onions: Peel onions and cut in halves, quarters, or slices. Roast over charcoal, on a gas grill, or on an ungreased griddle until charred and softened. Line the griddle with foil if desired for easier cleanup.
To toast garlic: Cook unpeeled whole cloves on an ungreased griddle, turning often, until they are soft and colored, about 15 minutes. Peel.