Cod Wrapped with Napa Cabbage with Ponzu Sauce

1 pound Cod, cut into 4 equal fillets
8 Napa cabbage leaves
2 tablespoons minced fresh ginger (3/4 teaspoon ginger per fillet)
1/2 cup diced carrot (1 tablespoon per fillet)
4 teaspoons chopped chives (1/2 teaspoon per fillet)
1/2 teaspoon salt
1/2 teaspoon freshly ground black pepper
Ponzu sauce:
2 tablespoons lime juice
2 tablespoons low-sodium tamari sauce
2 tablespoons water
1 tablespoon rice vinegar
1 teaspoon minced ginger
2 teaspoons sugar

In a metal or bamboo steamer basket, steam Cod for 2 minutes. Remove from steamer and halve. Place cabbage leaves in steamer basket and cook for 5 minutes or until tender. Lay cabbage leaves on a flat surface. Place 3/4 teaspoon ginger, 1 tablespoon carrots, and 1/2 teaspoon chives on each cabbage leaf, followed by 1/2 fillet of Cod. Season with a pinch of salt and pepper. Roll, folding in sides to enclose Cod. Steam for 4 to 5 more minutes or until fish is cooked through.
Combine all ingredients for ponzu sauce in a blender container and puree. Strain, if desired. Serve 2 tablespoons ponzu sauce with 2 Cod, wraps.