This gooey and decadent butternut squash gratin has a creamy baked brie center, crunchy pecan topping and crisp puff pastry crust. It's also a beautiful eye-catching seasonal appetizer or side dish for your next holiday gathering.
This butternut squash gratin combines some of the best seasonal flavors: sweet squash, crunchy pecans, creamy brie, crisp puff pastry. This makes it a perfect holiday appetizer or side dish to add to your next Thanksgiving menu.
I love the tastes of this dish and also the somewhat rustic presentation. The overhanging bits of puff pastry look really nice but you also can't help but want to pick them off and dunk them into that melted brie in the center.
Truly a great pick for a holiday dish as it combines all the best flavors of the season.
The nice thing about a gratin is that it can be fairly simple. In principle you just need the chosen vegetable being used and the béchamel (or add cheese and it's a Mornay sauce).
- Whole butternut squash: peel, cut lengthwise and scoop out the seeds
- Premade puff pastry: the piece shown here is 34 by 26cm / 13 by 10 inches and weighs 270 grams / 9.5 ounces. It's placed in an oval baking dish that measures 24 cm / 9.4 inches at its longest point. You will need to adjust accordingly depending on the puff pastry you find and the baking dishes you have on hand.
- Hard cheese like gruyere
- Soft cheese like brie or camembert
Please see recipe card for quantities.
There are three main steps involved:
- Precook the squash
- Prepare the bechamel
- Bake the assembled gratin
The order you do things in isn't very impactful but I would suggest making the bechamel while the squash is precooking.
If the bechamel sits it might get a bit lumpy. You can usually resolve this by whisking it vigorously again over medium heat. If it get's too thick add more milk one tablespoon at a time while whisking. Full troubleshooting tips are in my post on bechamel.
Precooking the Butternut Squash
For best results I recommend precooking the squash for two reasons.
First, to make sure it's cooked. Since the puff pastry could cook before the squash does: the last thing you want is raw squash in puff pastry.
More importantly, like many vegetables, butternut squash releases some water while cooking.
That water can make the gratin watery, so it's best to cook the squash separately so you can discard the water.
Peel the butternut squash, cut it lengthwise and scoop out the center. Prebake it on a parchment lined baking sheet following the instructions in the recipe card below.
Once the squash is cooked and cooled, slice it thinly on the horizontal plane before placing it into the puff pastry.
Place the cooked squash into the puff pastry lined baking dish. Place the brie in the center (for a gooey, melted middle) or scatter it around for more even brie flavor.
Preparing the Béchamel
The only hands-on part of this recipe (besides cleaning and slicing the squash is making the béchamel.
Making the béchamel is straightforward but you can see detailed information and troubleshooting tips in my post on making perfect bechamel.
Make a roux with the butter and flour.
Whisk the milk in.
Mix in the salt and gruyere cheese.
Pour the cheese béchamel over the squash in the roasting dish and scatter crushed pecans on top.
Any oven safe roasting dish will do.
I used a Staub cast iron oval roasting dish which is 24 cm / 9.4 inches at its longest point. It was just the right size with room to spare.
Storage & Reheating
Can be stored in the fridge in an airtight container for 3-4 days. Best reheated in the oven at 175 C / 350 F for 10-15 minutes. Pro tip: sprinkle some more gruyere and pecans on top to recreate the golden, caramelized crust.
You can also reheat in the microwave in a pinch.
Gratin is best served out of the oven. If it sits too long the béchamel eventually firms up.
When timing your meal, try to put the gratin in the oven 25-30 minutes before you intend to eat it. That way you can put it on the table when it's at its peak.
Looking for a dish to pair with this side? Try these:
Looking for other side dish recipes like this? Try these:
Butternut Squash Gratin in Puff Pastry
- 1 butternut squash prebaked
- 1.5 tablespoons olive oil
- 1 package puff pastry 270 grams or 10oz
- 500 ml milk
- 45 grams butter
- 45 grams flour
- 100 grams gruyere grated
- 0.5 teaspoons salt or more to taste
- 100 grams brie cheese or camembert cheese
- Preheat oven to 200 C / 390 C.
prepare the butternut squash
- Feel the butternut squash and scoop out the seeds. Place it facedown on a parchment lined baking sheet and bake for 20 minutes or until fork tender.
make the béchamel
- Heat the butter in a saucepan over medium heat until melted and beginning to bubble.
- Add the flour and whisk together until it forms a consistent paste (the roux). Keep stirring the roux for 1-2 minutes to cook. It should begin to smell nutty.
- Pour the milk over the roux and whisk vigorously and consistently. The milk can be poured in either all at once or ⅓ at a time - both ways are fine.
- Keep whisking until the bechamel thickens (3-4 minutes). If lumpy, whisk more vigorously. See post for troubleshooting details.
- Stir in the gruyere and salt.
- Taste the béchamel and add more salt as needed, keeping in mind it will also need to be seasoned enough for the squash.
assemble the gratin
- Lay the puff pastry out in the roasting pan.
- Slice the butternut squash thinly then arrange it over the puff pastry in the roasting pan.
- Pour the béchamel over the squash and then crumble the pecans on top.
- Reduce the oven temperature to 180 C / 360 F before putting the gratin in. Bake for at least 30 minutes or until the top is golden. If it browns too much in some spots, reduce the heat and roast until an even golden brown.