A traditional enchilada sauce will go with any filling or topping you choose, and either style of tortilla. Taste the sauce after you make it and add more salt if needed. (If too thick, add water; if too thin, thicken it with a flour-and-oil roux.) Pasilla chiles are available in Mexican grocery stores or well-stocked supermarkets. Prep and Cook Time: about 30 minutes.
Toast chiles in a hot oven (400°) for 3 or 4 minutes. Shake out seeds. Cover with 5 cups warm water; soak until soft. Place chiles and water in a blender with garlic, oil, salt, oregano, and cumin. Whirl until smooth (or grind in a food processor). Pour into a pan; add tomato purée. Simmer 10 minutes.