This recipe for savory butternut squash casserole with sweet potato and feta is a delicious, easy vegetarian side dish with a variety of flavors and textures. The golden, roasted butternut squash cubes and the creamy sweet potatoes get mixed with savory feta cheese to create a mouthwatering gratin. This heartwarming dish is perfect for any occasion and not just Thanksgiving!
Butternut squash doesn't usually comes to mind when talking about the Mediterranean cuisine, but there are many savory Mediterranean recipes using this winter squash, like this fall-staple creamy pumpkin risotto with feta (it also works with butternut!).
So, if you want to try a vegetarian side dish with Mediterranean vibes (that can also be served as main course if you don't eat meat), these delicious savory roasted butternut squash cubes with feta and sweet potatoes (also known as gratin) will not disappoint you.
Depending on the quantity you're making, you may have some leftover squash which you can use to make an easy butternut squash soup with sweet potato and coconut milk. Another option is to make a homemade pumpkin puree for your pies which freezes exceptionally well.
😍 Why this recipe works
This sweet potato and butternut squash casserole with feta checks all the boxes:
✓ Easy: this is one of those casserole recipes where you add the ingredients in the casserole and bake in the oven. This is basically an one-pan meal, only instead of a pan you'll use a casserole.
✓ Tasty: The savory taste of the feta and thyme pairs perfectly with the subtle sweetness from the vegetables, and all this deliciousness is covered by a crunchy breadcrumb and parmesan topping.
✓ Healthier: Just like sweet potato, butternut squash is a rich source of vitamins, minerals, fiber and antioxidants. Plus, feta cheese is a healthier option compared to hard cheeses because it's lower in fat.
✓ Not soggy: This squash casserole is not watery nor soggy, simply because you bake the vegetables without any water, broth or milk. You only need a bit of olive oil!
For this sweet potato and winter squash recipe you'll need the following simple ingredients:
You can read about the butternut squash and white sweet potato substitutions in the next paragraph.
Garlic: Two whole crushed garlic cloves, are enough to flavor this dish. For a stronger taste you can also mince them (but you'll have to add them at a later time so that they don't get burned).
Fresh thyme: you can also use dried if you can't find fresh.
Parmesan cheese (or any other cheese used): It's better to by a whole slice and grate it yourself, because in most cases the quallity and flavor will be much better.
Onion: Any onion will do, whether it's red, white or sweet onion.
Bread: Though the quantity isn't much, if you follow the Mediterranean Diet, opt for whole wheat bread. If you're serving this casserole to someone who can't eat gluten, choose a gluten-free bread.
🥣 Substitutions / Variations
Here are some substitutions and variations you can make for this oven roasted butternut gratin:
Squash: Feel free to use more squash varieties such as yellow squash, acorn squash, and pumpkin.
White sweet potato: Any other sweet potato variety will do. Alternatively, you can also use a Russet potato.
Feta cheese: Squash and feta cheese are meant to be together, but you can also try this recipe with a semi-hard goat cheese.
Parmesan cheese: A sharp cheddar or a nice gruyere will also give the cheesiness needed.
Breadcrumbs: Even if you don't have a food processor or chopper you can make breadcrumbs by crumbling a slightly stale bread with your hands. Alternatively you can use panko or crushed saltine crackers.
Thyme: Oregano can replace thyme in most recipes. You can also try rosemary or fresh sage but I haven't personally tried them myself.
Pine nuts: You can substitute them with chopped pecans, walnuts, almonds or hazelnuts.
Bacon variation: Oven roasted butternut squash pairs perfectly with the smoky flavor of bacon. Cook the bacon in a skillet until crispy, chop it in small pieces and add it to the breadcrumb mixture.
Follow this easy step-by-step guide to make a perfect butternut squash and sweet potato casserole every time:
Step 1: Prepare the vegetables. Trim the edges of the butternut squash and peel it with a peeler. Slice it in half, scrape the seeds with a spoon and cut it in 1-inch cubes. Cut the sweet potato into the same size cubes for even baking.
Step 2: Add all the vegetables into the casserole and season with the olive oil, the salt and the black pepper. Mix well until all the vegetables are coated with the oil and bake in the oven. Gently stir the vegetables halfway through roasting.
Step 3: Make the topping. Add all the ingredients for the topping to a bowl and mix to combine.
Step 4: Take the casserole out of the oven, add the cubed feta cheese and very gently mix with a spoon.
Step 5: Using your hands or a spoon, sprinkle the topping over the surface of the casserole and return to the oven for additional 5-10 minutes or until the surface is golden brown. Take out of the oven, let it rest for 5 minutes and serve. Garnish with fresh herbs if desired.
👨🍳 Expert Tips
Peeling and cubing butternut squash can be challenging due to its tough skin. To make it easier, you can microwave the whole squash for a minute or two to soften the skin slightly before peeling and cubing.
Cut the butternut squash and sweet potato into uniform cubes to ensure even cooking. This will prevent some pieces from overcooking while others are undercooked.
Slightly stale bread (1-2 days old) will crumble much better than a fresh loaf.
Don't stir the squash to much inside the baking dish, especially during the end of baking, because once it's soft, it can become mushy very easily.
Don't add the thyme from the beggining because it may burn in the oven.
Turn on the broiler 2-3 minutes before you take the casserole out of the oven. It will make the topping golden brown and more crunchy. Just keep an eye on it because it can burn very quickly, especially the pine nuts.
The easiest way to peel a butternut squash is to use a vegetable peeler. If the squash has a very tough skin, microwave it for 1-2 minutes so that it softens a little.
Another way is to trim the edges of the butternut and put it standing up on a chopping board. Using a sharp knife, cut off the skin staring from the top and going down. Remember to keep your hands out of the way of the knife.
According to The Flavor Bible, the following flavors go very well with butternut squash. I took the liberty to divide them into two categories.
To enhance the savory notes try pairing it with: olive oil, garlic, thyme, allspice, bacon, bay leaf, Parmesan cheese, goat cheese, onion, black pepper, sage, spinach, breadcrumbs.
To enhance the sweet notes try pairing it with: cinnamon, nutmeg, honey, cloves, leeks, brown sugar, butter, ginger, coconut milk, cream.
There are many ways to add moisture to casserole recipes, such as adding water, chicken broth or cream. Cream is probably the best way to do that because water or broth can make the casserole watery or soggy, whereas the cream has the ability to thicken when cooked.
Another way is to add bechamel sauce mixed with parmesan cheese. This will make your dish very creamy, cheesy, and finger-licking good!
How many days will this casserole last in the fridge?
Once cold, you can transfer this casserole gratin in an airtight container and store it in the refrigerator for 3-4 days. If you want the topping to be as crunchy as the first day, you should reheat it in the oven. Otherwise, reheating it in the microwaves will also do.
I don't suggest storing this butternut pumpkin casserole recipe in the freezer because the texture will not be as good after thawing.
If you tried this easy Sweet Potato and Butternut Squash Casserole Recipe or any other recipe on my website, please leave a 🌟 star rating and let me know how it went in the 📝 comments below. I love hearing from you!
Butternut squash casserole with sweet potato & feta
- 1 casserole approximately 10 inches x 7 inches (26cm x18cm)
For the casserole:
- 6.5 cups (750 g) butternut squash (in 1-inch cubes)
- 3 cups (300 g) white sweet potato (in 1-inch cubes)
- 1 (110 g) onion (roughly chopped)
- 2 garlic cloves (crushed)
- 2 tablespoons (28 g) olive oil
- 1 ½ teaspoon fine salt
- ½ teaspoon bleck pepper (freshly ground)
- 1 teaspoon minced fresh thyme (or dried thyme)
- 1.5 cups (225 g) feta cheese (in ½ inch cubes)
For the topping:
- 1 cup (100 g) breadcrumbs
- ½ cup (50 g) Parmesan cheese
- 2 tablespoons (28 g) olive oil
- 2 tablespoons (20 g) pine nuts
For garnish (optional):
- Fresh thyme, (or chopped chives or parsley)
- Preheat your oven to 400°F (200°C) and prepare the vegetables.
- Trim the edges of the butternut squash and peel it with a peeler. Slice it in half, scrape the seeds with a spoon and cut it in cubes.
- Add the butternut squash, the sweet potato, the onion, the garlic, the olive oil, the salt and the black pepper to the baking dish.Mix well until all the vegetables are coated well with the oil and bake in the oven for approximately 40-45 minutes or until fork tender (time will depend on oven and size of the casserole).Gently stir the vegetables halfway through roasting.
- In the meantime, add the breadcrumbs, the Parmesan, the olive oil and the pine nuts to a bowl and mix to combine.
- When the vegetables are fork tender, take the casserole out of the oven and try to find the two garlic cloves and discard them (unless you want to eat them). After that, add the cubed feta and the thyme and very gently mix with a spoon.
- Sprinkle the topping over the vegetables and return to the oven for additional 5-10 minutes or until the surface is golden brown. Take out of the oven, let it rest for 5 minutes and serve. Garnish with fresh herbs if desired.
- Sweet potato: any other sweet potato variety or even a Russet potato will do.
- Pine nuts: You can substitute them with chopped pecans, walnuts, almonds or hazelnuts.
- Don't stir the squash to much inside the baking dish, especially during the end of baking, because once it's soft, it can become mushy very easily.
- Turn on the broiler 2-3 minutes before you take the casserole out of the oven. It will make the topping golden brown and more crunchy. Just keep an eye on it because it can burn very quickly, especially the pine nuts.
- If you have a slow oven you may have to increase the temperature to 425°F (220°C).