- 1 1/2 pounds butternut squash, peeled and sliced 1/4-inch thick
- 2 tablespoons olive oil
- Salt and pepper
- 3 tablespoons thyme, picked
- 1 1/2 pounds Yukon Gold potatoes, washed and sliced 1/4-inch thick
- 1 cup milk
- 1 cup heavy cream
- 1/4 cup butter
- 1 1/2 cups grated gruyere
- 1 cup Parmesan
- Preheat oven to 425°F, and prepare a 9x9 baking dish with butter.
- In a bowl, toss together butternut squash slices with olive oil, salt, pepper and thyme. In another bowl, toss together Yukon Gold potatoes with olive oil, salt, pepper and thyme. Set aside.
- In a pot, heat milk, cream and butter to a simmer. Set aside.
- Begin layering gratin, starting with a 1/4 cup of cream mixture, followed by a layer of squash, a handful of gruyere and a sprinkling of Parmesan. Repeat alternating layers of squash and potatoes, finishing the top with extra cheese and a sprinkling of thyme.
- Cover with foil and bake for 20 minutes. Check doneness with a paring knife or toothpick in the middle. Remove foil and cook another 20 minutes until golden and bubbly.