Soak the fish in ice water for 15 to 20 minutes, or place it in a colander in the sink under cold running water for 15 to 20 minutes. Pat dry with paper towels.
In a small saucepan, bring the veal stock to a boil. Boil until the garlic is soft and the veal stock is reduced to 1/3 cup, 15 to 20 minutes
Place the flour in a large dish and season with salt and pepper. Dredge the fish fillets in the flour. Heat butter in a skillet. Add the fish, skin side up, and cook for 1 minute, then turn and cook for 6-8 minutes, or until the fish flakes nicely with a fork. Remove from the heat.
Meanwhile, add the remaining 2 tablespoons butter to the veal stock and heat over very low heat until the butter has melted; do not let boil.
Finely shave the truffle and scatter the shavings over the cod and into the cracks between the flakes of fish. Place the cod on warm plates. Drizzle with the garlic-veal glace and serve.