Rich and creamy, with the scent of Alba's finest truffle, this soup is a decadent joy to sip on a cold autumn night. If you don't feel like making croütes---large croutons or slices of toasted bread--omit, and simply add a spoonful of the truffle paste to each bowlful. Don't stir; let each person spoon up the soup, adding little bits of the truffle essence with each mouthful of creamy soup. Be careful, though; truffles -especially white ones are considered an aphrodisiac. (Don't say you weren't warned.)

1. To make the croütes: Heat the oven to 350°F. Arrange the sliced bread on a baking sheet and drizzle lightly or brush with olive oil. Bake for about 15 minutes or until light and toasty. Turn over and repeat until the bread is crunchy. Remove from the oven and set aside.

2. In a large saucepan, combine the potatoes, cauliflower, and broth. Bring to a boil, then reduce the heat to medium and cook until the vegetables are tender.

3. Remove from the heat. With a slotted spoon, transfer the vegetables to a food processor or blender, and whirl to make a smooth purée, adding enough of the liquid for smoothness. You could also use a hand-held blender to purée the soup. For a silkier, smoother texture, put the mixture through a tamis or sieve. Return the puréed mixture to the pot along with the remaining broth.

4. Add the cream to the soup and heat together.

5. Serve the hot soup in individual bowls. Spread each croüte with the truffle paste and float one on top of each bowl of soup. Serve right away.