For the ranchero sauce: Cover the ancho and guajillo chiles with boiling water in a heat-safe medium bowl. Let them soak until just softened and the water turns a light brown color, about 10 minutes.
Gently tear the chiles into large chunks, keeping the seeds and stems intact if possible, and put them in a blender. Add the tomatoes, cilantro, garlic, jalapeño, lime juice and 1 teaspoon salt to the blender. Fill the can from the tomatoes halfway with water and swirl it gently to wash all the tomato off the sides.
Add the tomato water to the blender and blend the mixture until very smooth.
Pour the mixture into a medium saucepan and bring to a boil over medium-high heat. Reduce the temperature to low and simmer, stirring often so as to not let burn, until the sauce has reduced by a quarter and slightly thickened, about 45 minutes (you should have about 3 cups of sauce). Taste and adjust seasoning to taste, the agave will smooth out any bitterness. |