Though most initiates to Mexican cooking probably start with a recipe for tomato salsa, I’d encourage this tomatillo one as a first foray. Besides being clearly authentic, it’s easier: Ripe tomatillos are easier to find than ripe tomatoes; tomatillos don’t get peeled; they give a salsa a consistently lovely thickness; and they come out a better texture than tomatoes when chopped in the blender or food processor.

For a salsa that’s the quintessence of freshness and spiciness, make the recipe that follows with just a half pound of raw tomatillos, roughly chop them, then coarsely purée them in a blender or food processor with all the rest of the ingredients (left raw), and add a tablespoon or two of water (it should be the consistency of a relish or fresh chutney). Clearly, this all-raw version is very quick to make, but you need to enjoy it within an hour or so.

Steps

1. Roast the key ingredients: Lay the tomatillos on a baking sheet and place 4 inches below a very hot broiler. When the tomatillos blister, blacken, and soften on one side, about 5 minutes, turn them over and roast on the other side. Cool completely on the baking sheet.
2. Roast the chiles and garlic on an ungreased griddle or heavy skillet over medium heat, turning occasionally, until blackened in spots and soft, 5 to 10 minutes for the chiles, about 15 minutes for the garlic. Cool, then pull the stems from the chiles and peel the garlic.
3. Make the purée: Scrape the roasted tomatillos (and any juices that have accumulated around them) into a food processor or blender, along with the roasted chiles and garlic. Pulse the machine until everything is reduced to a rather coarse-textured purée — the unctuously soft tomatillos will provide body for all the chunky bits of chiles and garlic.
4. Scrape the salsa into a serving bowl, then stir in between ¼ and ½ cup water, to give the sauce an easily spoonable consistency. Scoop the onion into a strainer, rinse under cold water, shake off the excess, and stir into the salsa, along with the cilantro. Taste and season with salt and a little sugar.