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Butternut squash gratin is everything you’d want in a cozy casserole dish. Cheesy, creamy, flavoured with thyme and garlic and extremely delicious!
This delicious casserole works beautifully as a side dish to your Thanksgiving or Christmas feast. For another approach to gratin, give Cauliflower Gratin a try!

Let’s talk about everything that is warm, cozy and comfy because our life demands it right now. With summer receding and autumn closing in, this season can have a bit of melancholy about it.
But it also means that some of my favourite produce is now in season, and with that, I get to have some fun with some all timers like butternut squash. And making the most of seasonal butternut squash is what this recipe is all about!
Baked butternut squash recipe
This creamy butternut squash casserole ticks all the boxes. The inspiration came to me via my favourite potatoes au gratin recipe.
This recipe is actually closer to potatoes dauphinoise. Although there are a lot of similarities, potatoes dauphinoise are distinguished by the use of raw rather than cooked potatoes. Traditional dauphinoise recipes don’t use cheese, but I thought that a bit of cheddar was worth adding.

The dish comes from the Dauphine region of France and is made from sliced and layered potatoes cooked in butter, heavy creamy and garlic. I decided to lighted up the recipe by using butternut squash instead of potatoes.
We loved this version even more than the traditional one. The sweetness of butternut squash complimented by nutmeg and countered by the garlic was no match for plain potatoes. The flavour was far richer and more complex.
How to make it
The method for making this gorgeous dish is very straightforward. Mix cream with nutmeg, crushed garlic clove, thyme sprigs and bay leaves and bring it to a boil. Take off the heat and let infuse for 10-15 minutes. Peel, deseed and slice butternut squash and layer in a buttered dish.
Pour the herb and garlic infused cream over the squash, cover with a tin foil and bake at 350F/ 180C for 30 min. Uncover and sprinkle with any type of sharp cheese. I used mature white cheddar. Bake for 30 minutes longer uncovered.

Recipe Tips and Notes
- Use a large and shallow This is an affiliate link.baking dish for this recipe. A rectangular 9 inch X 13 inch works well. Butternut squash tends to release too much liquid during the baking and is not nearly as starchy as potatoes. So if it is stacked high, the liquid doesn’t evaporate, which throws off the creamy consistency. I would avoid deep dishes for this recipe.
- Avoid the temptation to substitute heavy cream for single or half and half cream. The full fat cream is needed to thicken properly as the casserole cooks and to avoid curdling.
- Slice the butternut squash thinly, approximately a quarter inch thick. It should not be cut into cubes.
- You can make this casserole a day ahead and reheat it shortly before you are ready to sit down to dinner. Cover it with aluminium foil and heat for 10 minutes at 400F/200C, then uncover heat for 10 minutes longer.

Serving suggestions
A gratin casserole like this is a hefty side dish, so it goes best with a robust piece of meat or other main dish. It’s not difficult to guess this baked butternut squash goes with almost anything but let me highlight my favourite pairings.
I usually serve butternut squash casserole as a side dish to a holiday meal, especially around Thanksgiving. I that case, it’s perfect with a roast turkey or prime rib roast.
For other times of the year, try this amazing spatchcock roast chicken with potatoes, which will go wonderfully with a creamy dish like this butternut squash. Or this one pan rosemary chicken and potato dish will also compliment my creamy squash bake.
I have also tried it with pork roast and Tenderstem broccoli, along with a loaf of fresh baked bread. It made for a stunning meal, worthy of a family gathering or Sunday roast!
Storage and leftovers
The leftovers will keep fresh in the fridge up to 5 days. The flavours can even improve over time as they have more opportunity to meld together.
I recommend reheating in an oven preheated to 400F/200C for 10 minutes covered with aluminium foil. Then remove the foil and cook it uncovered for another 10 minutes.
More vegetable side dishes
Butternut Squash Casserole (Gratin)

Equipment
- This is an affiliate link.9×13 baking dish
Ingredients
- 400ml / 1¾ cups cups double cream/whipping cream, no half and half or single cream
- 2 This is an affiliate link.bay leaves
- a few thyme sprigs
- 1 garlic clove, crushed
- 1/2 tsp This is an affiliate link.nutmeg
- 1 tbsp butter
- 1kg / 2lbs large butternut squash, peeled and thinly sliced
- 100g / 1 cup mature white Cheddar or your favourite cheese, grated
Instructions
- Preheat the oven to 350F/180C. Mix the heavy cream with nutmeg, crushed garlic clove, thyme sprigs and bay leaves and bring it to a boil. Take off the heat and let infuse for 10-15 minutes.
- Peel, deseed and slice a large butternut squash and layer half of it in a large and shallow buttered dish. Pour half of the herb and garlic infused cream over the squash. Then add the second layer of butternut squash and cover with the remaining cream. Cover with tin foil and bake at 350F/ 180C for 30 min.
- Uncover and sprinkle with grated cheese. Bake for 20-30 minutes longer uncovered until the cheese is melted and golden and cream is bubbling around the edges.
Notes
- Do not substitute heavy cream with half and half or single cream.
- I recommend using a large and shallow baking dish for this recipe. A rectangular 9 inch X 13 inch works well.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Hi. What was I supposed to do with the butter? Otherwise a lovely recipe Barbara
Hi Barbara, 1 tablespoon of butter is for “buttering a large and shallow dish” in step 2. I am glad you enjoyed it!
My family love this recipe. This will be my new go to instead of the yam side dishes for Thanksgiving. and
Christmas
I love hearing this!! ๐
Can I use Hubbard or some other heritage squash?
You can use any squash, Christine as long as the flesh is not too watery.
This recipe is absolutely delish! ๐
Can this dish be frozen?
Yes, you can freeze it, just make sure you reheat at lower temperature of 325F to prevent the cream from splitting.
Heya,
it was delicious alright – but my cream separated ๐
didnt affect the taste after a lil mixing, but wasnt pretty to look at…
15% fat cooking creme…too thick?
Thx
My guess it’s separated because the cream wasn’t thick enough. It should be at least 37g fat content or higher. Low fat cream like half and half or light cream do not work in this recipe.
I love butternut squash, what a delicious gratin!
This looks absolutely delicious, Julia. I love butternut squash in all forms, so I’ll be trying this one!
Thank you, Jennifer! I do too and am always trying to find new ways of enjoying it!
There’s a special pleasure in cooking foods that are just barely out of season, this one looks so comforting, and the way my husband cranks up the air conditioning, I know I’m going to crave this!
I felt the same, Sue. I hesitated to cook butternut squash because it is out of season but it’s so delicious and filling-perfect food when you are trying to watch those calories!
This honestly looks like my idea of food heaven. Beautiful!
Thank you, Helen! I have to agree it was quite heavenly. ๐