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.
I first served this dish on a chilly autumn evening and it quickly became a family favorite for its rich, savory flavors and satisfying texture.
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.
- Prepare 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 the sliced onions and kosher salt. Cook stirring occasionally for 30 35 minutes until the onions are deeply golden and soft. Sprinkle with sugar about halfway through to encourage caramelization.
- Add Vinegar and Thyme:
- Stir in the balsamic vinegar and fresh thyme. Cook for 2 minutes then remove from heat.
- Prepare Squash for Filling:
- Remove squash from the oven and carefully turn cut side up. Reduce oven temperature to 375°F (190°C).
- Fill Squash:
- Evenly distribute the caramelized onions among the squash cavities. Top each half with grated Gruyere cheese.
- Bake Filled Squash:
- Return the filled squash to the oven and bake for 15 20 minutes or until the cheese is melted and golden brown at the edges.
- Garnish and Serve:
- Remove from the oven. Garnish with fresh parsley and additional thyme leaves before serving.
Save This recipe always brings the family together, with the aroma filling the kitchen and everyone eager to dig in.
Notes
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 check cheese labels to confirm. Vegetarian-friendly. No nuts or soy in the base recipe but verify all ingredient labels for cross-contamination if needed.
Save This dish is a perfect balance of sweetness and savory richness sure to impress.
Recipe FAQs
- → How do I achieve perfect caramelized onions?
Cook sliced onions slowly over low heat with butter and olive oil, stirring occasionally until golden and soft, about 30-35 minutes. Adding a pinch of sugar halfway helps enhance sweetness.
- → What is the best method to roast acorn squash?
Brush halves with olive oil, season with salt and pepper, place cut side down on a baking sheet, and roast at 400°F until fork-tender, about 35-40 minutes.
- → Can I use other cheeses instead of Gruyere?
Gruyere melts beautifully and adds a nutty flavor, but similar cheeses like Emmental or Fontina work well as substitutes.
- → How do fresh herbs enhance this dish?
Fresh thyme added during onion cooking and parsley as a garnish brighten the rich flavors with aromatic, earthy notes.
- → Is this dish suitable for gluten-free diets?
Yes, all main ingredients are naturally gluten-free; just ensure the cheese is certified gluten-free if needed.