2 large sweet potatoes
2 ancho chiles
1/4 cup chile water (see recipe for details)
scant 1/2 cup mayonnaise
1 teaspoon paprika
1/4 teaspoon cayenne
1/8 teaspoon oregano
1/8 teaspoon comino
1 1/2 tablespoons blue cheese salad dressing (optional)
Wrap the sweet potatoes in foil and bake at 350°F for 1 - 1 1/2 hours or till tester goes all the way through. Remove from oven and cool. Slice in half and, with a spoon, scrape the insides out and place in a blender jar. Reserve the skins.
Rinse the ancho chiles. Cut open; remove and discard stems and seeds. Soak the chiles in a bowl of hot water for 20 minutes. Taste the chile water. If it has a bitter taste, discard it; otherwise set it aside.
Add the chiles, mayonnaise, spices, and salad dressing to the blender jar with the sweet potatoes and purée. If the mixture is too thick, add the chile water (or plain water if you discarded the chile water).
Place the skins of the sweet potatoes on a baking sheet, and spoon the puréed mixture over them. Bake at 350°F for 20-30 minutes or till tops are just crisp and golden.