Creamy sweet potato and butternut squash gratin

    1 hour 15 min

    Layer sweet potatoes and butternut squash with a cream sauce and Asiago cheese for a colourful twist on potato gratin.

    25 people made this

    Serves: 6 

    • 2 sweet potatoes, quartered lengthwise
    • 1 butternut squash, quartered and seeded
    • 2 tablespoons olive oil, or as needed
    • 3 tablespoons butter
    • 1/2 onion, chopped
    • 2 tablespoons plain flour
    • 475ml milk
    • 1 1/2 teaspoons minced fresh sage, or more to taste
    • 1 pinch garlic salt, or to taste
    • freshly ground black pepper to taste
    • 25g grated Asiago cheese

    Prep:20min  ›  Cook:55min  ›  Ready in:1hr15min 

    1. Preheat oven to 180 C / Gas 4. Grease a square baking dish.
    2. Brush sweet potatoes and squash with olive oil. Arrange sweet potatoes on a baking tray; set squash aside.
    3. Bake sweet potatoes in the preheated oven for 5 minutes. Add squash to sweet potatoes; cook until almost tender, 10 to 15 minutes. Remove and cool.
    4. Heat butter in a saucepan over medium heat; cook and stir onion until tender, about 10 minutes. Add flour, milk and sage; season with garlic salt and black pepper. Cook and stir until flour is dissolved and sauce is thickened, 5 to 10 minutes.
    5. Remove and discard skins from sweet potatoes and squash. Thinly slice sweet potatoes and squash. Arrange sweet potato slices in the bottom of the prepared baking dish. Layer half the squash on top of sweet potatoes. Pour a little less than half the cream sauce over squash. Sprinkle with half the Asiago cheese. Repeat layering with remaining squash, cream sauce and Asiago cheese, respectively. Cover with foil.
    6. Bake in the preheated oven for 25 minutes. Remove foil and bake until cheese is melted and bubbling, about 10 more minutes.


    If it seems like there is not enough sauce after preparing the second layer, you can pour some milk over the top to create a little more liquid.

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    Reviews & ratings
    Average global rating:

    Reviews in English (17)


    Excellent. Due to time constraints, I handled the pre-baking differently: First I peeled then thinly sliced the squash and potatoes with food processor blade, then microwaved for 5 minutes with a little olive oil. Everything else I did as written. Start to finish in about 45 minutes.  -  24 Oct 2012  (Review from Allrecipes US | Canada)


    I used this recipe but changed a couple things.. I added mushrooms to the sauce as well as a few other spices. In addition to that when layering the pan I added spinach and ricotta. I'll post pictures after its been baked off. Great recipe I thank you for the sharing  -  27 Jan 2013  (Review from Allrecipes US | Canada)


    This dish was so tasty. I added a carrot along with the sweet potatoes and butternut squash. The combinations of flavors make this an excellent dish.  -  08 Sep 2012  (Review from Allrecipes US | Canada)