WHISK garlic, hoisin sauce, soy sauce, seasoned rice wine vinegar, ginger, salt and pepper in a large bowl.
ADD Catfish to mixture and marinate for 10 minutes.
While the Catfish is marinating, HEAT oil in a nonstick pan over medium-high heat.
ADD onions and water chestnuts.
COOK for 7 minutes.
REMOVE Catfish from the marinade and place in pan.
COOK for 5 minutes.
FLIP and cook an additional 7 minutes or until Catfish is cooked through.
SPOON into lettuce boats and GARNISH with green onion.