1. Combine first 8 ingredients in a small bowl. Cover and chill thoroughly.
2. Combine lemon juice and sesame oil; brush evenly over both sides of fillets. Place fillets in an 11- x 7- x 1 1/2-inch baking dish coated with cooking spray. Bake, uncovered, at 450° for 15 minutes or until fish flakes easily when tested with a fork.
3. Transfer to a serving platter. Spoon tomatillo mixture over fillets. Serve immediately.