Stewed Chicken in a Mustard Greens-Spinach Sauce

Cooks in north Indian restaurants in the United States (and in many parts of the Western world) stew boneless pieces of chicken with pureed spinach, cream, and spices. I like to include mustard greens for a more complex-tasting sauce with a slightly bitter edge to it. I leave the cream out to make sure the dish is not only healthier, but also an unusual one that you can enjoy frequently without guilt. Some Naan would be just great with the meal.