PREHEAT oven to 325° F. Grease 13 x 9-inch baking dish.
HEAT 1 tablespoon olive oil in large nonstick skillet over medium-high heat. Add onion; cook, stirring frequently, until tender and golden brown. Remove from skillet; set aside.
SEASON fish with salt and pepper. Add remaining oil to same skillet and cook fish until browned on both sides. Remove from heat. Place fish in prepared baking dish. Sprinkle with thyme, basil and anise. Top with reserved onion rings. Combine milk and water in small glass measure; pour over fish. If desired, season with additional salt and pepper.
BAKE for 20 minutes or until fish flakes easily with a fork.