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 dish has become a favorite in our home because of its rich flavors and hearty satisfaction that even non-vegetarians enjoy.
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 Sharing this dish with family creates warm, memorable dinners filled with comfort and flavor.
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
Chef's 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 a cozy, satisfying dish ideal for cooler months or whenever you want a gourmet vegetarian meal.
Recipe FAQs
- → How do I ensure the onions caramelize properly?
Cook sliced onions slowly over medium-low heat, stirring often. Adding a pinch of sugar helps enhance browning without burning, resulting in rich caramelization.
- → What’s the best way to roast the acorn squash?
Roast the squash halves cut side down coated with olive oil and seasoning. This concentrates sweetness and softens the flesh for a tender texture.
- → Can I substitute Gruyere cheese with another type?
Gruyere melts beautifully and adds a nutty flavor, but Emmental or mozzarella are good alternatives offering similar creaminess.
- → How long does it take to prepare the dish?
The total time is about 1 hour and 20 minutes, including 20 minutes prep and roughly an hour roasting and cooking the onions.
- → What herbs complement the flavor profile?
Fresh thyme and parsley add brightness and balance the richness of the cheese and caramelized onions, enhancing the overall taste.