Description

This Sage Butternut Squash Gratin is a creamy, savory casserole featuring thinly sliced butternut squash layered with a fragrant sage-infused cream sauce and parmesan cheese. Baked until golden and crispy on top, it’s an elegant yet comforting side dish perfect for fall and holiday meals.

Ingredients

Scale

Squash

2 lb (900g) butternut squash, peeled and sliced to 1/8 inch half-rounds

Cream Sauce

3 tablespoons butter
1 large shallot, minced
4 garlic cloves, roughly chopped
1 tablespoon all-purpose flour
1 cup low-sodium vegetable stock
1 cup heavy whipping cream
15 sage leaves
1/2 teaspoon pepper
1/2 teaspoon onion powder (optional)

Cheese & Garnish

3 oz (100g) grated parmesan cheese
1 teaspoon chopped chives, for garnish (optional)

Instructions

Prep the butternut squash: Peel and slice the butternut squash into thin 1/8 inch half-rounds. Scoop out the seeds as you slice, reserving the bottom of the squash for another use if desired.
Make the roux and sauce: In a small saucepan, melt the butter over medium heat, then cook the minced shallot and chopped garlic until fragrant, about 1 to 2 minutes. Stir in the flour and whisk continuously to form a roux, which will thicken and increase in volume.
Add liquids and seasonings: Gradually whisk in the vegetable stock until smooth. Then add the heavy cream, pepper, onion powder (if using), and sage leaves. Stir gently without boiling until the sauce becomes smooth and fragrant.
Prepare the baking dish: Grease a 9 x 13-inch baking dish with a small knob of butter. Pour a third of the cream sauce on the bottom, sprinkle a little parmesan cheese over it, then arrange the butternut slices on top in overlapping rows.
Layer and cover: Drizzle the remaining two-thirds of the cream sauce evenly over the layered squash. Cover the dish with parchment paper as a barrier if foil touches the top, then seal with foil to keep the moisture in.
Bake covered: Bake the gratin in a preheated oven at 400ºF (200ºC) for 20 minutes with the cover on to allow the squash to cook through.
Add topping and finish baking: Remove the foil cover, sprinkle the remaining parmesan cheese evenly over the top, then bake uncovered for another 10 minutes until the top turns golden brown and crispy.
Garnish and serve: Remove from the oven, sprinkle with chopped fresh chives if desired, and serve immediately family style for a warm, comforting side dish.

Notes

For a nuttier flavor, try substituting half of the parmesan cheese with gruyere or fontina.
If you prefer a thicker gratin, reduce the cream slightly or add a little more flour to the roux before adding liquids.
Make sure to slice the butternut squash evenly for uniform cooking.
Sage leaves can be chopped finely and mixed into the sauce for more intense flavor.
This gratin pairs beautifully with roasted meats or as a vegetarian main when served with a side salad.

Prep Time: 15 minutes
Cook Time: 30 minutes
Category: Side Dish
Method: Baking
Cuisine: American

Keywords: butternut squash gratin, sage gratin, winter squash casserole, creamy squash bake, vegetarian side dish, holiday side dish