In large bowl, mix broth, tomatoes, melted butter, garlic, garam masala, ginger, salt and ground red pepper; stir in chicken and onions. Pour mixture evenly over rice in baking dish; cover with foil. Bake 40 minutes; stir. Replace foil; bake 15 to 20 minutes longer or until rice is tender, chicken is no longer pink in center and mixture is heated to at least 165°F in center of casserole. Stir; top with cilantro. Serve with cashews and sour cream.