Makes About 4 Cups

Remove stems and seeds from the chiles. Dry roast the chiles in a 250°F oven for 3 to four minutes. Add the roasted chiles to water that has been heated to just below boiling. Allow them to sit for 20 minutes or until soft. Drain, reserving the liquid.

Puree the roasted, re-hydrated chiles. Blacken the tomatoes in a skillet or under a broiler (about 5 minutes). Sauté the onion in the oil over low heat until browned.

Put chiles in a blender and add blackened tomatoes, onion, garlic, cumin, oregano, and salt. Add 1 cup of the reserved Chile soaking water (taste the Chile soaking water before adding it, if it is not bitter, use it, if it is bitter, use plain water or chicken stock instead). Puree to a smooth paste, adding more Chile water, water, or chicken stock if necessary.

Add oil or lard to a high-sided pan, and heat until almost smoking. Refry sauce at a sizzle for 3 to 5 minutes, stirring continuously. Do not allow sauce to get too thick; add water if necessary. Sauce can be kept for up to 1 week in the refrigerator.