Cashew Chicken Curry

Notes: a can of coconut milk can be substituted for the yogurt, and is just as good, if not better. If using coconut milk, add in along with the tomatoes instead of at the end. Curry can be made ahead and kept in fridge for a few days or frozen prior to adding yogurt and cashews. 

Adapted from Gourmet.
Serves 4-6. 

2 tablespoons butter
2 medium onions, finely chopped (2 cups)
2 large cloves garlic, finely chopped
1 tablespoon grated fresh ginger
2 tablespoons curry powder
1/2 teaspoon salt
1 teaspoon cumin
Pinch of cayenne
1 whole chicken, cut up into parts, or about 4-5 chicken breasts
1 (14.5-oz) can diced tomatoes
1/4 cup fresh cilantro, chopped
3/4 cup cashews, plus more for garnish
3/4 cup plain yogurt (or a can of coconut milk--see note above)

Heat butter in a wide heavy pot over moderate heat. Add onions, garlic, and ginger, and stir until softened, about 5 minutes. Add curry powder, salt, cumin, and cayenne, and cook, stirring, for 2 minutes. Add chicken and cook, stirring to coat, about 3 minutes. Add tomatoes, including juice, and cilantro and bring to a simmer. Cover and simmer gently, stirring occasionally, until chicken is cooked through, about 40 minutes (time will be greatly reduced if using boneless, skinless chicken breasts).

Just before serving, pulse cashews in a food processor until finely ground. Add to curry along with yogurt. Simmer gently, uncovered, until sauce is thickened, about 5 minutes.