- 1 large butternut squash, peeled and sliced into 1/8 inch rounds
- 2 russet potatoes, peeled and sliced into 1/8 inch rounds
- 3 T olive oil
- 6 cloves garlic, minced
- 2 tsp fresh thyme, minced
- 1 tsp salt
- 1/2 tsp freshly ground pepper
- 4 T butter
- 1 1/2 c heavy cream
- 1/2 c whole milk
- 1 1/2 c shredded gruyere
- 1 c shredded Parmesan
- Preheat oven to 425 degrees and grease 8 x 8 casserole dish.
- Peel the butternut squash and potatoes.
- Using a mandolin or very sharp knife, cut the squash and potatoes into 1/8 inch thick rounds or half rounds and place into a large mixing bowl. Toss with a few T olive oil.
- Heat a saucepan over medium heat. Add butter, cream, milk, and garlic. Cook until butter is melted, stir in fresh thyme, and set aside.
- Start layering the potatoes and squash into the dish, alternating colors in 1 even later. Top each layer with salt, pepper, a little gruyere and parmesan. Repeat until you use up all of the taters and squash.
- Pour the cream mixture all over the potatoes and squash, and sprinkle the top with the remaining gruyere and parmesan.
- Cover gratin with foil and bake for 25 minutes. Remove the foil and bake an additional 25-30 minutes, or until top is golden brown and bubbling.
- Let it set for 5-8 minutes before serving.