Soak plank in water for at least 1 hour.
Preheat grill to medium-high heat.
Drizzle fillets with oil; then season with garlic, salt and pepper.
Place soaked plank on grill, and cover with a metal pan. Cook for 3 minutes. Remove pan, and flip plank.
Place green onions on plank. Add lemon slices and seasoned fillets, and return metal pan over plank. Cook for 5 minutes or until fish is flaky.
Serve with Hoppin’ John.
Hoppin’ John:
Brush onion slices with olive oil; cook in a hot grill about 5 minutes on each side or until grill marks appear. Coarsely chop onion.
In a large bowl, combine all ingredients, stir in Tasso Vinaigrette and serve with cedar plank catfish.