Caramelized Onion Gruyere Squash

Featured in: Everyday Comfort Dishes

Acorn squash halves are oven-roasted until tender and then filled with slowly caramelized onions infused with balsamic vinegar and fresh thyme. Generously topped with grated Gruyere cheese, the squash is baked until the cheese melts into bubbly golden edges. This cozy dish showcases a balance of sweetness from onions and savory creaminess from Gruyere, garnished with fresh herbs for an elegant touch. Perfect as a satisfying vegetarian main, it combines simple techniques to elevate seasonal squash.

Updated on Sun, 23 Nov 2025 15:51:00 GMT
Roasted Caramelized Onion Gruyere Acorn Squash, a close-up of cheesy, golden squash halves brimming with onions. Pin Recipe
Roasted Caramelized Onion Gruyere Acorn Squash, a close-up of cheesy, golden squash halves brimming with onions. | fordishes.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 squash recipe has become a family favorite, especially during the cooler months when warm, hearty meals are welcome.

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.
Warm, cheesy Caramelized Onion Gruyere Squash, showcasing tender acorn squash filled with caramelized onions and fresh herb garnish. Pin Recipe
Warm, cheesy Caramelized Onion Gruyere Squash, showcasing tender acorn squash filled with caramelized onions and fresh herb garnish. | fordishes.com

Sharing this dish around the table has created many warm family moments and stories worth repeating.

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.

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.

Savory Caramelized Onion Gruyere Squash: fork-tender, glistening squash stuffed with melted cheese, perfect autumn vegetarian recipe. Pin Recipe
Savory Caramelized Onion Gruyere Squash: fork-tender, glistening squash stuffed with melted cheese, perfect autumn vegetarian recipe. | fordishes.com

This recipe combines comfort and elegance in every bite making it perfect for special occasions or everyday dinners.

Recipe FAQs

How do I caramelize onions evenly?

Cook onions slowly over medium-low heat, stirring occasionally to prevent burning. Adding a pinch of sugar helps enhance caramelization and sweetness.

What’s the best way to roast acorn squash?

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

Can I use a different cheese than Gruyere?

Yes, mild melting cheeses like Fontina or Comté work well as alternatives, offering a similar creamy texture and flavor balance.

Should I peel the acorn squash before roasting?

No need to peel. The skin becomes tender when roasted and helps keep the squash intact for stuffing.

How do fresh herbs enhance this dish?

Fresh thyme and parsley add aromatic brightness and a fresh contrast to the rich caramelized onions and melted cheese.

Caramelized Onion Gruyere Squash

Roasted acorn squash halves filled with sweet caramelized onions and melted Gruyere cheese.

Prep Duration
20 mins
Cooking Duration
60 mins
Complete Time
80 mins
Recipe by Fordishes Ava Reynolds


Skill Level Medium

Cuisine Modern American

Makes 4 Number of Servings

Diet Details Vegetarian Option, Gluten-Free

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 Gruyere cheese, grated
02 2 tablespoons fresh thyme leaves, plus additional for garnish
03 1/4 cup chopped fresh parsley, optional

Directions

Step 01

Preheat oven and prepare baking sheet: Preheat oven to 400°F. Line a baking sheet with parchment paper.

Step 02

Season and roast squash: Brush cut sides of 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 to 40 minutes until tender when pierced with a fork.

Step 03

Caramelize onions: In a large skillet over medium-low heat, melt unsalted butter with olive oil. Add sliced onions and kosher salt, cooking slowly for 30 to 35 minutes, stirring occasionally. About halfway through, sprinkle sugar to promote caramelization.

Step 04

Add vinegar and herbs to onions: Stir balsamic vinegar and fresh thyme into the onions. Continue cooking for 2 more minutes, then remove from heat.

Step 05

Prepare squash for filling: Remove squash from oven and carefully turn cut side up. Reduce oven temperature to 375°F.

Step 06

Assemble filled squash: Divide caramelized onions evenly among the squash cavities. Top each half with grated Gruyere cheese.

Step 07

Bake stuffed squash: Return filled squash halves to the oven and bake for 15 to 20 minutes until cheese is melted and golden at the edges.

Step 08

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

Needed Equipment

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

Allergy Info

Double-check ingredients for allergens and speak with a healthcare provider if you're unsure.
  • Contains dairy from butter and Gruyere cheese
  • Naturally gluten-free ingredients; verify cheese labels for gluten content

Nutrition Information (per serving)

For informational use only—doesn't replace personalized medical direction.
  • Calories: 340
  • Fats: 19 g
  • Carbohydrates: 32 g
  • Proteins: 12 g