Sweet Potato Gratin
Restaurant Phoebe, Montpelier, Vermont
4 sweet potatoes, peeled
2 Idaho or Russet potatoes, peeled
2 quarts heavy cream
1/2 cup chopped fresh thyme
1 teaspoon nutmeg
1 tablespoon salt
1 teaspoon black pepper
2 cups fresh grated parmesan cheese
Butter for the baking dish
Pour cream into a bowl. Add nutmeg, salt, and pepper.
Slice both the sweet and the regular potatoes very thinly, and place directly into the seasoned cream.
After all potatoes are sliced, start neatly layering them into the greased 9” x 11” x 3-inch baking dish. Reserve the cream remaining in the bowl. Mix some of the regular potatoes into each layer, as the starch in these will help the gratin set after cooking.
After you have the first layer built, sprinkle parmesan cheese and thyme on to the potatoes.
Build another layer, and repeat with the cheese and thyme. Build the gratin right up to the edge of the baking dish.
Pour reserved cream over gratin until it is just below the level of the potatoes.
Cover gratin with foil and bake at 350 degrees F for 1.5 hours or until a skewer passes through the gratin easily.
Let gratin rest for 20 minutes, uncovered.
Sprinkle with remaining cheese and thyme and bake for an additional 6-8 minutes at 400 degrees or until cheese is melted.