Chicken Curry with Cashews

INGREDIENTS

• 1/4 cup chopped fresh cilantro
• 1 (14.5-ounce) can diced tomatoes
• 1/2 teaspoon cayenne
• 1 tablespoon finely chopped peeled fresh ginger
• 1 teaspoon ground cumin
• 2 medium onions, finely chopped (2 cups)
• 3/4 cup cashews (1/4 pound)
• 3/4 cup plain whole-milk yogurt
• Garnish: chopped fresh cilantro
• 2 large garlic cloves, finely chopped
• 1 (3 1/2- to 4-pound) chicken, cut into 10 serving pieces
• Accompaniment: cooked basmati or jasmine rice
• 2 teaspoons salt
• 1/2 stick (1/4 cup) unsalted butter
• 3 tablespoons curry powder