Coat large skillet with non-stick cooking spray. Heat over medium heat. When skillet is hot, put fillets in a single layer in the bottom. Cook for 30 to 45 seconds and turn. Sprinkle with parsley and salt and pepper. Dissolve orange juice concentrate in hot water. Pour over the top of the fillets.
Lift edges of fish with spatula to allow orange juice underneath. Reduce heat and gently simmer until fish flakes easily (approximately 5 to 6 minutes). Remove fish from skillet and keep warm. Reduce stock left in skillet until it forms a light syrup, by raising heat and stirring constantly. (Light syrup will coat the back of the spoon when spoon is removed from pan.) Pour over warm fish and serve.
