Cheddar and thyme butternut gratin is a simple, but surprisingly flavorful side dish that pairs well with just about anything. It's a delicious new way to use winter squash!
Heat the butter in a medium-sized skillet over medium to medium-high heat. Once hot, add the onion and cook until starting to soften, about 3 to 5 minutes, stirring occasionally. Add the garlic and cook 1 minute more, stirring constantly.
Turn off the heat and stir in the thyme, salt, pepper, and nutmeg. Stir in the butternut squash and use a fork or potato masher to mash about half of it. Stir it all together.
Transfer the squash mixture to a 2 cup-capacity gratin dish. Pour the cream or half and half on top and sprinkle on the cheese.
Place the gratin dish on top of a foil-lined baking sheet and bake until bubbling throughout, about 15 minutes. Broil for a couple minutes to brown the top more.
Serve warm.
Notes
What Kind of Butternut to Use: For this recipe, you can use store-bought cubed butternut squash (and roast it yourself), or frozen cubed butternut (and steam it in the microwave), or get a whole butternut squash (and peel, de-seed, and cube it, and then toss it with a drizzle of olive oil and roast it in a preheated 425F oven until tender, about 20 to 30 minutes). Or you can use leftover roasted butternut squash cubes if you have them on hand!
Storage: You can store leftovers covered in the fridge for up to 4 days.
Reheating: This butternut casserole reheats well in the oven; to do so, cover it with foil and bake in a preheated 350F oven until warm throughout.