This traditional Mexican dish features whole baked ancho chiles stuffed with a delicious chicken filling and topped with a cream sauce.
Preheat oven to 350 degrees. Slit an opening in each ancho from stem to tip, being careful not to tear the skin; carefully remove seeds and ribs, and discard.
Combine the water, vinegar, piloncillo, cinnamon, and salt in a medium saucepan; bring to a boil over high heat. Reduce heat to low; simmer 5 minutes. Remove from heat. Add anchos; cover, and let stand 8 to 10 minutes. Transfer to a paper-towel-lined plate to drain.
Spoon filling into each chile; arrange in a baking dish. Bake chiles until heated through, about 15 minutes. Bring crema and onion to a boil in a small saucepan over medium-high heat. Reduce heat; simmer 8 minutes. Pass through a fine sieve into a bowl; stir in cilantro. Pour sauce over anchos, and serve.
Martha used 8 to 10 ancho chiles, 3/4 teaspoon coarse salt, 1/2 cup finely diced onion, and 1/4 cup finely chopped fresh cilantro, plus sprigs for garnish.