In a small bowl combine mustard seeds, garlic, ginger, chile, salt, turmeric, curry powder, and, if desired, fenugreek. Stir in water; set aside.
Meanwhile, heat oil in large nonstick skillet over medium-high heat. Add fennel and cumin seeds. Cook for 10 seconds. Carefully add mustard seed mixture. Bring to boiling; reduce heat. Simmer, uncovered, for 2 minutes. Add fish and return to boiling. Cook and stir for 4 to 6 minutes or until fish flakes easily when tested with a fork. Serve hot with plain basmati rice. Makes 4 servings.
Plain Basmati Rice
Rinse basmati rice. Drain. In a 2-quart saucepan combine rice and water. Let stand for 30 minutes. Add butter and salt. Bring to boiling over medium-high heat; reduce heat. Simmer, covered, for 10 to 15 minutes or until water is absorbed. Fluff rice with fork before serving.