1hoja santa leaf or small bunch of epazote(optional)
2tablespoonslard or olive oil
1poundcrabmeat, or whatever else you want this sauce on.
Get a large, heavy frying pan or comal very hot. Partially char the stale tortillas; you want lots of black marks, but don't blacken them totally. If you are using tostadas, no need for this.
Briefly toast the ancho chiles, pressing down on them with a spatula. You want to just see some blistering, so maybe 10 to 30 seconds per side. Submerge all the toasted chiles in warm water.
Arrange the onions, garlic and tomatoes on the hot pan to char them. You want serious blackening here. The tomatoes will take the longest, and don't be tempted to move them too soon or you'll leave all the good blackened bits in the pan. If that happens, scrape it up immediately and set the scrapings aside.
In another pan, toast the pumpkin seeds over medium-high heat until they start to pop. Move to the bowl of a blender. Crush up the toasted tortillas and put them in the blender, too, along with the cloves, achiote and anise seeds, if using. Add enough water to the blender to turn this all into a runny paste. TIP:If you happen to be braising some meats, use some of the broth instead of water. Pour the contents of the blender into a large bowl.
When the vegetables are nicely charred, peel the garlic, then add everything to the blender with the soaked chiles and the hoja santa leaf, if using. Add some of the chile soaking water and blend this to a puree, too. Add it to the bowl and mix well. Add salt to taste.
Heat the lard in a pot over medium-high heat, and when it's hot, add the chirmol. Stir well to combine and drop the heat to low. Let this simmer 15 to 20 minutes. Serve over cooked crabmeat or whatever meat you have, garnished with cilantro or chives.