Heat oil in non-stick saucepan over medium heat. Cook eschallot and garlic gently until fragrant but not brown. Stir in black bean sauce, rice wine and soy sauce. Bring to boil and cook until reduced by half. Remove from heat and stir in vinegar; set aside.
Pat fish dry. Rub with sesame oil and sprinkle with pepper. Preheat barbecue for high heat and lightly oil grate.
Barbecue fish for about 5 minutes per side or just until cooked through. Sprinkle with coriander. Serve with sauce poured over top.