Prep: 8 minutes; Cook: 10 minutes; Other: 10 minutes
1. Preheat oven to 475°. Place a jelly-roll pan in oven while preheating.
2. Combine first 3 ingredients in a medium bowl; stir with a whisk until foamy. Combine panko and sunflower seed kernels in a shallow dish. Dip fillets in egg white mixture; dredge in panko mixture. Place fish on a wire rack; let stand 10 minutes.
3. Remove jelly-roll pan from oven; coat pan with cooking spray. Coat fish with cooking spray; place on pan. Bake at 475° for 10 minutes or until fish flakes easily when tested with a fork or until desired degree of doneness. Serve with lemon slices, if desired.