Original recipe by Sunset magazine, edited by GKC
12 very large romaine lettuce leaves
2 tablespoons Dijon mustard
1/2 cup green olive tapenade or homemade 
1 pound halibut fillets (1 inch thick)
Heat grill to medium - about 375 degrees. Cook lettuce leaves 2 or 3 at a time in a pot of boiling water until ribs are flexible, 1-1/2 to 3 minutes and then transfer to a bowl of ice water. Lay leaves flat with smooth sides up on kitchen towels and pat dry.
Spread the 8 largest leaves with olive tapenade. Cut fish into 8 pieces, each about 2-1/2 inches wide. Place 1 piece at base of each leaf. Top each piece of fish with 1 teaspoon of Dijon mustard. If leaf isn't big enough to enclose fish, overlap leaf with another. Roll up each bundle from base, folding in sides (gently crack lettuce ribs if needed). Brush bundles with oil. Discard any extra leaves.
Grill bundles, turning once, until fish is just opaque, 8 minutes. Serve with lemon.
Halibut is so expensive so we like to save it for very special recipes like this one .