When I was testing this recipe in September, Daniel Boulud and his wife popped by Langdon Hall for an eight-course lunch, so I served some to him.

Jason Bangerter

His exact words were: “This is the best thing I have tasted in a very long time.” The dish has followed me for years. It was an instant success at Auberge du Pommier when I was chef there back in 2007, and when I moved to Luma, people followed just to ask for it there, too. Now they come for it at Langdon. I love truffles and I’m a bit of a mushroom freak, but the inspiration for the dish really got started in the early ’90s when I was an apprentice under John Higgins in the pastry kitchen at the King Edward Hotel. He was once chef for the Royal Family—and the parmesan shortbread biscuits served with this soup are just a savoury version of his Buckingham Palace shortbread cookies. The idea for the soup came later, when I was working in London for Anton Mosimann, one of the official caterers for the Royal Family. His mushroom risotto was one of Princess Di’s favourite dishes and was served on Will and Kate’s wedding day. While working for Mosimann, I made the dish over and over, at all sorts of events across Europe. It became very special to me. This soup is really all the ingredients from Mosimann’s risotto—made into soup form.

– Jason Bangerter

Makes
6 – 8 Servings

Start with the shortbread. Preheat oven to 180°C (360°F). In a mixing bowl, combine flour, butter, cheese, a little salt and pepper, and mix with your fingers until it balls up in large crumbs. Compress into a dough, cover tightly with plastic wrap, and set aside to rest in a cool spot for a minimum of 30 minutes. Transfer to a floured work surface and roll out to a thickness of about 50 mm (¼ inch). Cut out small disks with a cookie cutter and transfer to a baking sheet lined with parchment paper. Transfer to the middle shelf of the oven and bake until golden—about 15 minutes.

To prepare the soup, heat the oil in a large saucepan or Dutch oven over low heat, and sweat the onion, leek, celery, garlic and thyme. When the vegetables have wilted and softened, add the mushrooms and sweat until they release their juices. When that liquid has reduced almost completely, increase the heat and deglaze with Madeira. Reduce the wine by two-thirds and then add enough stock or water to generously cover the solids in the pot. Reduce heat, and simmer until the stock has reduced by one-third—about 15 minutes. Take the pot off the heat and let cool slightly. While the soup is still hot, transfer to a blender and purée, adding cold butter one piece at a time, alternating with drizzles of truffle oil, letting each addition emulsify completely before proceeding to the next. Pass the soup through a chinois or some other fine mesh strainer. Taste, and correct seasonings. If the purée is too thick, whisk in a little more stock. Set aside.

For the truffle cream, whip the cream until it thickens and forms soft peaks. Whisk in the truffle oil. Optional: Add the sherry and chives (for brightness in an otherwise earthy dish). Set aside.

To finish, heat the soup and divide between desired number of warm bowls. Top each with a spoonful or two of truffle cream, and sprinkle with your selected garnish. Place a piece of parmesan shortbread to one side, and serve.