Roasted tomatillo sauce base and salsa

Pull the husks off the tomatillos.

Lay the tomatillos, garlic in its husk, serranos and onion on a rimmed baking sheet, dry, with no oil.

Broil with the rack at the highest level about 6 minutes, until darkened on top.

Flip and roast the other side about 6 minutes; watch the garlic and chilies, which finish first, so nothing burns.

Cool a little and peel the garlic from its papery husk.

Cut up the onion and put everything in the blender with the juices from the pan and 1 teaspoon salt.

Blend to a coarse puree; this is the roasted tomatillo base.

For salsa: pour into a serving dish and thin with a little water.

Slice cilantro thinly, stems and all, and stir it in.

Refrigerated, it may set from the tomatillos' pectin; stir it, whisk it, or pulse in the blender to bring it back.

Taste and add more salt as needed.