Roast ingredients on a griddle (or very large skillet): As cooks would in southern Mexico, heat griddle or skillet over medium to medium-high, then lay a piece of foil on one side (for easy clean up) and put the tomatoes there. Lay the garlic and chile directly on the hot surface. Roast, turning everything periodically until everything is soft and blotchy blackened in places—10 to 15 minutes. Or roast ingredients under a broiler: Spread the tomatoes, garlic and chile on a rimmed baking sheet and roast about 4 inches below a hot broiler (my toaster oven works well here) until the tomatoes are blotchy blackened on one side, about 6 minutes, turn everything over and roast the other side.
Cool: When handleable, cut the cores from the tomatoes and pull off the blackened skin if you wish. Peel the garlic.
Crush the ingredients in a mortar: Work the garlic and chile back and forth with the pestle until you have a smooth puree. One by one, work the tomatoes into the mix, crushing them to a coarse puree. Or make the salsa in a blender or food processor: Turn on the appliance and drop in the garlic cloves and chile one by one. Scrape down the sides, then add the tomatoes (and any juices) and pulse until you have a coarse puree.
Finish and season: Scrape the salsa into a serving dish and add water a tablespoon at a time until it’s an easily spoonable consistency. If you’re using cilantro, gather it into a tight bundle and thinly slice across it (leaves and stems) until you run out of leaves. Chop the onion into about ¼-inch pieces. For the freshest flavor, rinse in a strainer under cold water to get rid of that unpleasant “oniony” flavor. Shake off excess water and add to the salsa along with the cilantro. Taste and season first with salt, usually about a scant teaspoon, then a little vinegar or lime if you think it needs it.
Playing around: Quite often, I slice and roast the onion along with the other ingredients. Rather than crushing/processing it with the chile and garlic, I chop it to add at the same time as cilantro. That’s what we do when we make our crazy-popular salsa huevona, though that salsa has double the chile and double the amount of onion, and everything is cooked on the grill rather than under a broiler. it’s smoky, spicy and sweet from roasted onion, everything hand chopped to make a coarse, very rustic salsa—no cilantro in that one. This is a place where different chiles can really shine, especially if you up the quantity from the minimal amount I listed above. Think about this salsa when you’re at a summer or fall farmers market. I love it with roasted habanero, but start with a half unless you’re really into spice.
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