Ingredients
1 pound Jerusalem artichokes, peeled and sliced 1/4-inch-thick and reserved in cold water until ready to use
3 cups milk
8 ounces creme fraiche
2 tablespoons freshly squeezed lemon juice
1 cup grated Gruyere cheese
1 tablespoon minced fresh thyme
1 teaspoon coarse salt
1/4 teaspoon freshly ground pepper
1/2 pound Yukon gold potatoes, peeled and sliced 1/4-inch-thick
5 ounces shallots, peeled and sliced thinly
5 ounces peeled chestnuts, halved lengthwise
4 slices white bread, lightly toasted, crusts removed, and torn into small bits (to make 1 to 1 1/4 cups)
Preparation
In a large saucepan, combine Jerusalem artichokes and milk. Bring to a boil, and reduce to a simmer, and cook for 10 minutes. Drain, reserving 3/4 cups of the milk.
Preheat oven to 450 degrees. In a medium bowl, whisk creme fraiche, reserved milk, lemon juice, 1/4 cup Gruyere, thyme, salt, and pepper. Add artichokes, potatoes, chestnuts, shallots; gently mix to combine. Transfer to a 6-cup shallow baking dish, and cover tightly with parchment-lined aluminum foil. Place on a rimmed baking sheet, and bake until artichokes are tender, about 1 hour. Remove foil, and sprinkle with breadcrumbs and remaining 3/4 cup cheese. Bake, uncovered, until golden brown, 8 to 10 minutes. Serve warm.