Save Acorn squash halves roasted until tender, stuffed with deeply caramelized onions and melty Gruyere cheese, and finished with fresh herbs—a comforting, gourmet vegetarian main perfect for any occasion.
This recipe quickly became a family favorite because it brings together sweet caramelized onions with rich Gruyere cheese in a simple yet elegant dish.
Ingredients
- Squash: 2 medium acorn squash, halved lengthwise and seeded, 2 tablespoons olive oil, 1/2 teaspoon kosher salt, 1/4 teaspoon ground black pepper
- Caramelized Onions: 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
- Filling and Garnish: 1 1/2 cups Gruyere cheese, grated, 2 tablespoons fresh thyme leaves plus more for garnish, 1/4 cup chopped fresh parsley (optional)
Instructions
- Preheat Oven:
- Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper.
- Roast Squash:
- Brush the cut sides of the acorn squash with olive oil. Season with kosher salt and black pepper. Place squash halves cut side down on the prepared baking sheet and roast for 35–40 minutes, or until the flesh is fork-tender.
- Caramelize Onions:
- Heat unsalted butter and olive oil in a large skillet over medium-low heat. Add sliced onions and kosher salt. Cook, stirring occasionally, for 30–35 minutes until onions are deeply golden and soft. Sprinkle with sugar about halfway through to encourage caramelization.
- Add Vinegar and Thyme:
- Stir in balsamic vinegar and fresh thyme. Cook for 2 minutes, then remove from heat.
- Prepare Squash for Filling:
- Remove squash from oven and carefully turn cut side up. Reduce oven temperature to 375°F (190°C).
- Fill Squash:
- Evenly distribute caramelized onions among squash cavities. Top each half with grated Gruyere cheese.
- Bake Filled Squash:
- Return filled squash to oven and bake for 15–20 minutes, or until cheese is melted and golden brown at edges.
- Garnish and Serve:
- Remove from oven. Garnish with fresh parsley and additional thyme leaves before serving.
Save This dish creates cozy family moments with everyone enjoying the melt-in-your-mouth flavors and inviting aroma filling the kitchen.
Notes
Roast squash cut side down to concentrate sweetness and enhance caramelization. Caramelize onions slowly over low heat to avoid burning and bitterness. Grate cheese yourself for the best melting texture. Easily doubled for meal prep or gatherings. Pairs beautifully with a green salad or crispy sourdough toast. Use certified gluten-free cheese if needed.
Required Tools
Chefs knife, cutting board, baking sheet, parchment paper, large skillet, wooden spoon, grater
Allergen Information
Contains dairy (butter, Gruyere cheese). Naturally gluten-free& vegetarian-friendly. No nuts or soy in the base recipe but verify all ingredient labels for cross-contamination if needed.
Save This recipe is a perfect blend of sweet and savory with simple steps that deliver an elegant meal every time.
Recipe FAQ Section
- → How do I caramelize onions properly?
Cook thinly sliced onions slowly over low heat with butter and olive oil, stirring occasionally until they turn deeply golden and soft. Adding a pinch of sugar helps enhance sweetness.
- → What is the best way to roast acorn squash?
Roast squash halves cut side down to concentrate sweetness and soften the flesh. This usually takes 35–40 minutes at 400°F until tender.
- → Can I use other cheeses instead of Gruyere?
Yes, semi-hard cheeses with good melting qualities like fontina or Swiss work well to complement the caramelized onions and squash.
- → How do fresh herbs enhance this dish?
Fresh thyme and parsley add bright, aromatic notes that balance the richness of the caramelized onions and melted cheese, lifting the overall flavor.
- → Is this dish suitable for gluten-free diets?
Yes, naturally gluten-free ingredients are used, but ensure the cheese is certified gluten-free to avoid cross-contamination.