The Sauce Reduce the cream until consistency is of medium thickness consistency in a sauce pan. Adjust the heat to medium, slowly whisk in the gooseliver terrine and remove from the heat. If the sauce is too thick, dilute with vegetable broth. Serve Prepare a pot of boiling salted water on stove. Once boiled, cook the fettucine until al dente about 4 minutes. Remove from the heat and drain away the water, mix it with the gooseliver sauce in a sauce pan and season with salt and pepper. Place it on a serving plate and sprinkle with truffle oil and garnish with grated black and white truffles. Serve immediately.