Juice lemon and set aside. In a small pot, whisk together lemon juice, lemon zest, wine, shallot and garlic.

Cook over high heat until reduced to half. Remove from heat, cool slightly. When lemon mixture is warm, cut in margarine and whisk together. Add parsley and season with salt and pepper.

Cover with plastic wrap and refrigerate for at least 30 minutes. Bring to room temperature before starting to grill the fish. Heat grill over high heat.

Brush the cooking grates clean. Brush fillets with olive oil and season with salt and pepper (brush with more olive oil if needed). Grill fish over medium-high heat for 4 minutes per side, until golden brown and fish flakes easily with a fork.

Place fish in plates and top with lemon sauce. Serve immediately over warm pasta or parboiled rice. Use shrimp instead of fish, if preferred.

Enjoy!