Mustard maple salmon

3 tbsp dijon mustard 3 tbsp maple syrup 1 tbsp balsamic vinegar 1/4 tsp salt 4 (6oz) salmon filets Cooking spray Combine first 4 ingredients in a large ziplock bag; add salmon. Seal and marinate for 20 minutes. Prepare grill or broiler. Remove salmon from the bag, reserving the marinade. Place salmon on a grill rack or broiler pan, coated with cooking spray or foil. Cook for 6 minutes on each side or until fish flakes easily when tested with a fork. Baste salmon occasionally with the reserved marinate.