Caramelized Onion Gruyere Squash

Featured in: Comfort Family Meals

This dish features acorn squash halves roasted to tender perfection, then filled with deeply caramelized onions that bring a rich sweetness. Melted Gruyere cheese adds a creamy, savory layer, while fresh herbs brighten the flavors. Cooking involves slow caramelizing of onions to develop depth, followed by baking stuffed squash until golden and melty. It's a comforting, elegant main that suits any occasion, especially for vegetarian and gluten-free preferences.

Updated on Sun, 23 Nov 2025 15:19:00 GMT
Golden-brown Caramelized Onion Gruyere Squash, stuffed and baked, offers a comforting, savory main dish. Save
Golden-brown Caramelized Onion Gruyere Squash, stuffed and baked, offers a comforting, savory main dish. | nomiqo.com

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 combines the sweetness of roasted acorn squash with rich caramelized onions and melted Gruyere cheese for an unforgettable 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:
Distribute caramelized onions evenly 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.
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This dish is a family favorite and brings everyone together around the table with its rich flavors and comforting textures.

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.

Melty Gruyere tops caramelized onions nestled in tender Caramelized Onion Gruyere Squash halves, ready to serve. Save
Melty Gruyere tops caramelized onions nestled in tender Caramelized Onion Gruyere Squash halves, ready to serve. | nomiqo.com

Enjoy this recipe as a flavorful and satisfying vegetarian main that impresses every time.

Recipe FAQs

How do I caramelize onions perfectly?

Cook sliced onions slowly over low heat with butter and oil, stirring occasionally to prevent burning. Adding a pinch of sugar helps deepen sweetness and color.

What’s the best way to roast acorn squash?

Roast squash halves cut side down on a baking sheet to concentrate sweetness and soften the flesh evenly.

Can I substitute Gruyere cheese?

Yes, cheeses like Emmental or Fontina offer similar melt and flavor, but Gruyere brings a unique nuttiness that complements the dish best.

How long should the squash be baked once stuffed?

After filling with onions and cheese, bake at 375°F for about 15-20 minutes until cheese melts and turns golden at the edges.

Are there tips for prepping ahead?

Caramelize onions and roast squash ahead, then assemble and bake just before serving for convenience and fresh results.

Caramelized Onion Gruyere Squash

Roasted acorn squash stuffed with sweet caramelized onions and melted Gruyere cheese, enhanced by fresh herbs.

Prep Duration
20 min
Cook Duration
60 min
Total Duration
80 min
Created by Chloe Bennett


Skill Level Medium

Cuisine Type Modern American

Portions 4 Serving Size

Dietary Details Vegetarian-Friendly, No Gluten

Ingredient List

Squash

01 2 medium acorn squash, halved lengthwise and seeded
02 2 tablespoons olive oil
03 1/2 teaspoon kosher salt
04 1/4 teaspoon ground black pepper

Caramelized Onions

01 2 large yellow onions, thinly sliced
02 2 tablespoons unsalted butter
03 1 tablespoon olive oil
04 1/2 teaspoon kosher salt
05 1/2 teaspoon granulated sugar
06 2 teaspoons balsamic vinegar
07 2 tablespoons fresh thyme leaves

Filling and Garnish

01 1 1/2 cups grated Gruyere cheese
02 1/4 cup chopped fresh parsley (optional)

Recipe Steps

Step 01

Preheat oven and prepare squash: Preheat oven to 400°F. Line a baking sheet with parchment paper. Brush cut sides of acorn squash with olive oil, season with kosher salt and black pepper, and place cut side down on the baking sheet. Roast for 35 to 40 minutes until tender.

Step 02

Caramelize onions: In a large skillet over medium-low heat, melt butter with olive oil. Add sliced onions and kosher salt, cooking slowly for 30 to 35 minutes while stirring occasionally. Halfway through, sprinkle with sugar to enhance caramelization. Stir in balsamic vinegar and fresh thyme, cook for 2 more minutes, then remove from heat.

Step 03

Fill and bake squash: Remove squash from oven and turn cut side up. Reduce oven temperature to 375°F. Fill squash cavities with caramelized onions, top evenly with grated Gruyere cheese. Return to oven and bake for 15 to 20 minutes until cheese is melted and golden around edges.

Step 04

Garnish and serve: Remove from oven and garnish with fresh parsley and additional thyme leaves before serving.

Tools Needed

  • Chef's knife
  • Cutting board
  • Baking sheet
  • Parchment paper
  • Large skillet
  • Wooden spoon
  • Grater

Allergy Information

Review all ingredients for allergen risks and check with your healthcare provider for guidance.
  • Contains dairy from butter and Gruyere cheese.
  • Naturally gluten-free; verify cheese labels for gluten content.

Nutrition Info (per portion)

Provided only for reference purposes—don’t substitute for professional medical guidance.
  • Energy: 340
  • Lipids: 19 g
  • Carbohydrates: 32 g
  • Proteins: 12 g