Roast the chicken legs in the preheated oven until the skin is crispy, and the meat is cooked through, 30 to 40 minutes.
While the chicken is roasting, puree the milk, sour cream, chipotle peppers, and chicken bouillon granules in a blender until smooth. Melt the margarine in a large pan over medium heat. Pour in the chipotle puree, bring to a simmer, reduce heat to low, and season with salt to taste. Add the cooked chicken legs, and simmer for about 10 minutes, until chicken has taken on the flavor of the sauce.
