Yield: 8 to 10 servings as an hors d'oeuvre

Method:

Heat the olive oil in a medium saucepan on low heat. Sauté the onions until soft, about 5 to 7 minutes. Add the mushrooms and raise the heat to medium-high. Sauté until soft, about 5 minutes. Add the stock, thyme, and garlic. Bring to a boil, then reduce the heat and simmer for 30 minutes.

Remove the thyme from the pan and discard. Using a slotted spoon, transfer the solids to a food processor. Add enough of the cooking liquid to cover the solids by an inch and blend. Add the half-and-half and butter and blend until smooth. Add a little more cooking liquid to reach the desired consistency. Season with salt and pepper.

If making the milk foam, heat the milk in a small saucepan until warm and vigorously whisk to create foam.

Pour the soup into small bowls or cappuccino cups. Spoon some milk foam on top of each bowl of soup. Garnish each bowl with a few drops of white truffle oil and sprinkle with chives.