Chile Colorado is a classic of Mexican and Tex-Mex cooking, and this recipe produces its essential foundation: a rich, slowly simmered sauce built from toasted guajillo and ancho chiles. The result is deep red and beautifully balanced — smoky and fruity from the chiles, warmly earthy from the cumin and oregano, and gently rounded by a light roux — mellow rather than sharply hot. It works right away as the base for beef chile colorado stews, or as a filling and seasoning for enchiladas and tamales.