Step 1

* Note 1: Use a cheese such as Mexican queso fresco; queso anejo; dry feta; pressed, salted farmer's cheese; or Parmesan cheese

Step 2

* Note 2: Use 3 to 6 (1/4 to 1/2 ounce) dried chiles chipotles colorados (chiles mortias), or 2 to 4 (1/4 to 1/2 ounce) dried chiles chipotles mecos, or 3 to 6 canned chiles chipotles en adobo.

Step 3

Make the Roasted Tomatillo Chipotle Salsa: Set an ungreased griddle or heavy skillet over medium heat. If using dried chiles, break off their stems. Toast chiles a few at a time: Lay on the hot pan, press flat for a few seconds with a metal spatula (they'll crackle faintly and release their smoky aroma), then flip and press down to toast the other side.

Step 4

Transfer the toasted chiles to a bowl, cover with hot water, and let rehydrate for 30 minutes, stirring regularly to ensure even soaking. Pour off all the water and discard. If using canned chiles, simply remove them from the adobo sauce that they are packed in.

Step 5

On a heavy ungreased skillet or griddle over medium heat, roast the unpeeled garlic, turning occasionally, until blackened in spots and soft, about 15 minutes. Cool, slip off the papery skins, and roughly chop.

Step 6

Preheat broiler with rack about 4 inches above. Lay tomatillos on a baking sheet, and place under broiler. When the tomatillos blister, blacken, and soften on one side, about 5 minutes, turn them over and roast on the other side. Remove from oven, and cool completely on the baking sheet.

Step 7

Scrape tomatillos (and any juices that have accumulated around them) into a molcajete, food processor, or blender, and add the rehydrated or canned chiles and the garlic. Combine until everything is thick and relatively smooth (detectable little bits will add textural interest).

Step 8

For a chunkier alternative, combine tomatillos with their juices and the garlic only until everything is coarsely pureed; chop the rehydrated or canned chiles into tiny bits, then stir them into the tomatillo mixture.

Step 9

Transfer salsa to a serving bowl, and add enough water to give the salsa an easily spoonable consistency, 3 to 4 tablespoons. Season with salt, and add sugar if you want to soften the tangy edge. (

Step 10

Makes about 1 1/4 cups)

Step 11

Warm the tortillas: Place a vegetable steamer in a large saucepan filled with 1/2 inch of water. Bring to a boil. Wrap tortillas in a heavy kitchen towel, lay them in the steamer, and cover with a tight lid. Boil 1 minute, turn off the heat, and let stand without opening for about 15 minutes.

Step 12

Prepare the filling: While tortillas are steaming, bring 3 quarts salted water to a boil in a large pot. Add greens, and cook until barely tender, 1 to 2 minutes. Drain in a colander, and spread out on a large plate or baking sheet to cool. When cool enough to handle, roughly chop.

Step 13

In a large skillet, heat oil over medium-high heat. Add onion, and cook, stirring frequently, until golden brown, about 10 minutes. Add garlic, stir for 1 minute, then add greens, and stir for about 1 minute, just long enough to heat them through. Season with salt.

Step 14

Prepare the tacos: Scoop the filling into a deep, warm serving dish, and sprinkle with cheese. Serve with the warm tortillas, salsa, and cilantro sprigs.

Step 15

This recipe yields 8 to 10 soft tacos.

Step 16

Comments: These tacos are a favorite of chef Rick Bayless, who first tasted them at a market stall in Toluca, Mexico, where they're considered to be good, old-fashioned peasant food.