Golden Potato and Porcini Gratin

• Recipe by Richard Betts

This indulgent gratin is the result of a trip Richard Betts took in 2006 to the Rhône Valley’s renowned winery Domaine Jean-Louis Chave, where his daughter Isabella found a giant porcini under an oak tree. "We took it to the winery and everyone got so excited because it was the first one of the season," says Betts. "That afternoon, all the workers split; Jean-Louis Lombard, the vineyard manager, said they were mushroom hunting. The next day there were flats of porcini." Lombard told Betts that most of the mushrooms would get sliced and dried and used in gratins throughout the winter. "I took that idea and ran with it," says Betts.

Ingredients

1. 1 cup dried porcini mushrooms (1 ounce)
2. 1 cup hot water
3. 1/2 cup dry white wine
4. 3 garlic cloves, halved
5. 4 thyme sprigs
6. 2 1/2 cups heavy cream
7. 1 1/2 cups freshly grated Parmigiano-Reggiano cheese (5 ounces)
8. 1 tablespoon kosher salt
9. 1/8 teaspoon cayenne pepper
10. 2 pounds Yukon Gold potatoes, peeled and sliced 1/8 inch thick on a mandoline

Directions

1. Preheat the oven to 350°. In a small bowl, cover the porcini with the hot water and let soak until softened, about 15 minutes. Using a slotted spoon, remove the porcini from the soaking liquid; discard the liquid. Rinse and coarsely chop the porcini.
2. In a large saucepan, combine the wine, garlic and thyme sprigs and boil over high heat until the wine has reduced by half, about 3 minutes. Add the cream, 1 cup of the grated cheese, the salt and cayenne and bring to boil. Remove from the heat and discard the thyme sprigs and garlic cloves.
3. Arrange half of the potato slices in an even layer in a shallow, 15-by-10-inch baking dish. Spread the porcini evenly over the potatoes. Top with the remaining potato slices. Pour the cream mixture on top and shake the dish to distribute the cream. Sprinkle with the remaining 1/2 cup of grated cheese. Bake for 1 hour and 10 minutes, or until the potatoes are tender and the top is richly browned. Let the gratin rest for 15 minutes, then serve hot.