Heat 1 tablespoon oil in a large frying pan over medium-high heat. Add onion paste, and sauté, stirring, for 4-5 minutes or until browned. Add ground cumin, garam masala and red chili powder. Saute for 1 minute. Stir in tomato paste, and sauté, stirring, for another minute. Add cashew paste, and sauté, stirring, for 1 minute. Add ½ cup water. Cook, stirring occasionally, until oil separates. Set aside.