Mole poblano is a complicated sauce, it takes a long time to make. Southern Mexican cooking can be very sophisticated, and Mexicans themselves shortcut the process by using store-bought moles. I don't recall it being used with beans- usually with chicken and other meats. I have put this here just for illustration; we have never had it outside of a restaurant.

MOLE POBLANO

4 dried Pasilla chiles
4 dried mulato or New Mexico chiles
1/4 pound ancho chiles
2 medium onions, chopped
2 garlic heads cut in half horizontally
2-4 medium tomatoes, peeled, seeds removed
1/2 pound tomatillos, husked and rinsed
2 tablespoons sesame seeds
1/2 cup peanuts
1/2 cup almonds
2 7-inch corn tortillas
1/4 cup raisins or more
Cinammon stick, 4 inches
1 teaspoon coriander seed
4-8 whole cloves
3 tablespoons oil
2-4 oz. bitter Mexican chocolate (or more, to taste)

Lay chiles in a single layer on a cookie sheet and bake in preheated oven at 300 F. until chiles lightly toasted and are flexible, 5-8 minutes. While still warm, discard stems and shake out the seeds.

Rince chiles and put in large bowl; add 8 cups boiling water and let stand until soft, 30 minutes or so. Drain and save liquid. Puree chiles a bit at a time, in food processor or blender adding 2 cups reserved chile-soaking liquid. Rub firmly through fine strainer into a bowl and discard residue.

Put onions, tomato, tomatillos, garlic (cut side down) on a cookie sheet and bake at 450 F turning occasionally, until the vegatables and tortillas have dark brown spots or edges. Pull off vegetable skins and discard.

Puree vegetable mixture, adding a total of 1 cup reserved chile-soaking liquid. Rub firmly through fine strainer into a bowl and discard residue.

Toast tortillas in a dry frypan over medium heat until they have brown spots; remove. Toast almonds & peanuts in the dry frying pan and set aside. Toast sesame seeds and spices last and remove.

Add oil to frypan. Add nuts, spices & raisins, stirring frequently. Tear up corn tortillas and add to the mixture. Continue cooking 5-10 minutes. Puree this mixture in a food processor or blender, adding remaining chile-soaking liquid.

In a large stockpot, mix the ingredients. Bring to a simmer on medium heat, cover and simmer to blend flavors, at least 2 hours, stirring often.

Chop chocolate, mix with sauce until melted. Use sauce within one week, or freeze. Or can the sauce.

From the net, I have forgotten where.