- 1 leek (white and pale green parts only), finely chopped
- 1 3/4 cups finely chopped shallot (10 ounces)
- 3 garlic cloves, finely chopped
- 2 cups dry white wine
- 2 large fresh thyme sprigs
- 1 1/4 ounces preserved black truffles (preferably winter truffles), finely chopped
- 4 cups chicken stock or low-sodium chicken broth
- 4 cups heavy cream
- 1/4 teaspoon black or white truffle oil, or to taste
- Wash chopped leek in a bowl of cold water, then lift out and drain (do not pat dry). Steam leek, shallot, and garlic (in any water clinging to leeks) in a 4-quart heavy saucepan, covered, over low heat, stirring occasionally, until softened, about 6 minutes. Add wine, thyme, and truffles and boil, uncovered, until most of liquid is evaporated, about 12 minutes.
- Add stock and boil until reduced to about 2 cups, about 25 minutes. Stir in cream and simmer, stirring occasionally, until reduced to about 2 3/4 cups, about 40 minutes. Pour mixture through a fine sieve into another saucepan, pressing on and discarding solids. Whisk in truffle oil and season with salt and pepper.