Heat the oil in a medium-sized sauté pan over medium-high heat until hot but not smoking. Fry the chiles, 1 or 2 at a time until puffed and brown, about 10 seconds. Do not let them burn or the Adobo will taste bitter. Shake off excess oil from the chiles and place in a medium bowl. Reserve the cooking oil. Add the boiling water to the chiles and let soak until soft, about 20 minutes. Toss occasionally to make sure all the chiles soften evenly.

Put the softened chiles, their soaking water, and all the remaining ingredients in a blender and blend until smooth. (You can use a food processor, but you will not get as smooth a texture.)

Heat 2 tablespoons of reserved chile oil in a large nonstick skillet over medium-high heat until hot but not smoking. Pour the blended mixture into the skillet and cook, stirring frequently, until it begins to reduce, sizzle, and become darkly colored, about 10 minutes. If it boils too vigorously, lower the heat. Keeps, tightly covered, several weeks in the refrigerator.