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 transforms simple ingredients into a cozy, flavorful dish that delights every time I serve it.
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
- Step 1:
- Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper.
- Step 2:
- 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.
- Step 3:
- Meanwhile, 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.
- Step 4:
- Stir in the balsamic vinegar and fresh thyme. Cook for 2 minutes, then remove from heat.
- Step 5:
- Remove squash from the oven and carefully turn cut side up. Reduce oven temperature to 375°F (190°C).
- Step 6:
- Evenly distribute the caramelized onions among the squash cavities. Top each half with grated Gruyere cheese.
- Step 7:
- 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.
- Step 8:
- Remove from the oven. Garnish with fresh parsley and additional thyme leaves before serving.
Save This dish always brings the family together around the table, sharing stories and savoring every bite.
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 always 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 recipe is sure to become a beloved classic in your vegetarian rotation.
Recipe Questions
- → How should I prepare the acorn squash for roasting?
Halve the acorn squash lengthwise and remove the seeds. Brush the cut sides with olive oil, season with salt and pepper, then roast cut side down to enhance sweetness and tenderness.
- → What is the best way to caramelize onions for this dish?
Cook thinly sliced onions slowly over medium-low heat with butter, oil, salt, and a pinch of sugar. Stir occasionally for 30-35 minutes until deeply golden and soft.
- → Can I substitute Gruyere cheese if needed?
This recipe works well with cheeses that melt smoothly and have a nutty flavor, such as Emmental or Fontina, though Gruyere provides a distinctive richness.
- → How do fresh herbs contribute to the flavor?
Fresh thyme and parsley bring brightness and an herbal note that balances the sweetness of the onions and richness of the cheese, enhancing overall depth.
- → What's a good side to serve with this squash dish?
A simple green salad or crusty sourdough toast complements the creamy, savory squash, adding texture and freshness to the meal.
- → Can this dish be prepared ahead of time?
Yes, you can roast the squash and caramelize the onions in advance, then assemble and bake just before serving to maintain freshness.