Step 1

Get a comal or flattop or griddle very hot and sear the skins of the poblanos and jalapenos. You will want to thoroughly blacken the poblano skins, but the jalapenos only need some charring for flavor. When the poblanos are nicely blackened, put them in a plastic bag to steam. Remove the jalapenos, chop and put into a blender

Step 2

Meanwhile, char the cut sides of the onion on the comal, as well as the garlic. When the onion and the skins of the garlic cloves have blackened, remove from the heat. Peel the garlic and put in a blender. Roughly chop the onion and put that in a blender. If you want to, char the cut sides of the tomatillos, too, although this isn't strictly needed.

Step 3

Use a butter knife to strip off the skins of the poblanos. Remove the seeds and stems and chop roughly. Add them to the blender.

Step 4

Chop the hoja santa leaves or mustard greens and add them to the blender. Add the remaining ingredients to the blender except for the lard. Puree well. You want this to be smooth. If you have a small blender you might need to do this in batches.

Step 5

Heat the lard in a large pan over medium-high heat. When it's hot, scrape the sauce into the pan. It will sputter and spit. Stir constantly until the lard has incorporated, then add water or broth slowly until the mixture has the consistency of melted ice cream. Add salt to taste and cook another 10 minutes or so. Serve poured over your meat or fish with some toasted pepitas and cilantro for garnish.