Introduction

This Onion Gruyere Squash is a cozy, flavorful dish perfect for fall or any time you crave a comforting vegetable side. Roasted acorn squash filled with sweet caramelized onions and melted Gruyere cheese creates a delicious balance of savory and sweet.

Two roasted acorn squash halves sit on a white plate, each filled with a thick, creamy layer of golden melted cheese that has a slightly browned, bubbly top. The bright yellow-orange color of the squash flesh contrasts with the dark, roasted brown edges of the skin. Fresh green herbs are sprinkled on the cheese, adding a touch of vibrant green. A sprig of fresh thyme lies next to the squash on the plate, and a silver fork rests beside the food. The scene is set on a white marbled texture surface. photo taken with an iphone --ar 4:5 --v 7

Ingredients

2 medium acorn squash, halved lengthwise and seeded
2 tablespoons olive oil
1/2 teaspoon kosher salt
1/4 teaspoon ground black pepper
2 large yellow onions, thinly sliced
2 tablespoons unsalted butter
1 tablespoon olive oil
1/2 teaspoon kosher salt
1/2 teaspoon granulated sugar
2 teaspoons balsamic vinegar
1 1/2 cups Gruyere cheese, grated
2 tablespoons fresh thyme leaves, plus more for garnish
1/4 cup chopped fresh parsley, optional

Instructions

Step 1: Preheat your oven to 400°F. Line a baking sheet with parchment paper for easy cleanup.
Step 2: Brush the cut sides of the acorn squash with olive oil. Sprinkle with kosher salt and ground black pepper. Place the squash halves cut side down on the baking sheet and roast for 35 to 40 minutes, until the flesh is fork-tender.
Step 3: While the squash roasts, heat unsalted butter and olive oil in a large skillet over medium-low heat. Add the sliced onions and kosher salt. Cook, stirring occasionally, for 30 to 35 minutes until onions are soft and deeply golden. Sprinkle granulated sugar halfway through cooking to help caramelize the onions.
Step 4: Stir in balsamic vinegar and fresh thyme leaves into the caramelized onions. Cook for another 2 minutes, then remove from heat.
Step 5: Remove the roasted squash from the oven and carefully turn them cut side up. Lower the oven temperature to 375°F.
Step 6: Evenly spoon the caramelized onions into the cavities of the squash halves. Top each with grated Gruyere cheese.
Step 7: Return the squash to the oven and bake for 15 to 20 minutes, until the cheese has melted and is golden with bubbly edges.
Step 8: Remove from the oven and garnish with fresh parsley and additional thyme leaves before serving.

Tips & Variations

Use a mix of Gruyere and sharp cheddar for a different cheese flavor and extra meltiness.
Swap balsamic vinegar for sherry vinegar for a milder tang.
For a nuttier twist, sprinkle toasted pine nuts or walnuts over the top before serving.
If you prefer a sweeter dish, drizzle a little honey over the onions before baking.

Storage

Store leftover stuffed squash in an airtight container in the refrigerator for up to 3 days. Reheat in the oven at 350°F until warmed through to preserve the texture of the squash and keep the cheese melted and bubbly.

How to Serve

Two halves of a stuffed acorn squash sit on a white plate. Each half has a dark green, slightly charred outer skin with a yellow-orange inner flesh. The squash is filled with a creamy, golden-brown cheesy mixture that is browned on top, showing some melted cheese bubbles and light crust. Small green herb leaves are sprinkled evenly on the cheese topping. Fresh herb sprigs are placed beside the squash halves, and a silver fork rests near the top edge of the plate. All of this is on a white marbled textured surface. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I prepare this dish ahead of time?

Yes, you can caramelize the onions and roast the squash separately in advance. Assemble and bake just before serving for best results.

Can I use a different type of squash?

Acorn squash works best because its shape holds the filling well, but small kabocha or delicata squash can also be used with slight adjustments to cooking time.