Description
This Caramelized Onion Gruyere Acorn Squash recipe is a comforting and elegant side dish perfect for fall and winter. Roasted acorn squash halves are filled with sweet, deeply caramelized onions enhanced with balsamic vinegar and fresh thyme, then topped with melted Gruyere cheese. The combination of savory, sweet, and aromatic flavors with the creamy texture of the roasted squash makes this dish a delightful addition to any meal.
Ingredients
Scale
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
- 2 tablespoons fresh thyme leaves, plus more for garnish
Topping & Garnish:
- 1 1/2 cups Gruyere cheese, grated
- 1/4 cup chopped fresh parsley (optional)
Instructions
- Prepare Oven and Pan: Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper to prevent sticking and for easy cleanup.
- Season and Roast Squash: Brush the cut sides of the acorn squash halves with olive oil, then season evenly with kosher salt and black pepper. Place the squash halves cut side down on the prepared baking sheet and roast in the oven for 35 to 40 minutes until the flesh becomes tender and can be easily pierced with a fork.
- Caramelize Onions: While the squash roasts, heat unsalted butter and olive oil together in a large skillet over medium-low heat. Add thinly sliced yellow onions and kosher salt. Cook the onions slowly, stirring occasionally, for about 30 to 35 minutes until the onions are soft, time releasing their natural sugars. About halfway through cooking, sprinkle the granulated sugar over the onions to help deepen the caramelization.
- Finish Onions with Vinegar and Thyme: Once the onions are deeply golden and caramelized, stir in the balsamic vinegar and fresh thyme leaves. Cook for an additional 2 minutes to blend the flavors, then remove the skillet from heat.
- Fill and Bake Squash: Carefully remove the roasted squash from the oven and flip each half cut side up. Lower the oven temperature to 375°F (190°C). Distribute the caramelized onions evenly into the cavities of each squash half, then sprinkle the grated Gruyere cheese generously over the top.
- Bake Filled Squash: Return the filled squash halves to the oven and bake for 15 to 20 minutes, or until the Gruyere cheese is fully melted, bubbly, and golden brown around the edges.
- Garnish and Serve: Remove from oven and garnish the squash with fresh parsley and extra thyme leaves if desired. Serve warm as a flavorful side dish or vegetarian main.
Notes
- Be patient while caramelizing onions; slow cooking is key to rich flavor.
- You can substitute Gruyere with Emmental or a mild Swiss cheese if unavailable.
- For a vegan version, use dairy-free butter and cheese substitutes.
- Acorn squash can vary in size; adjust roasting times accordingly.
- Leftovers store well in the fridge for up to 3 days and reheat nicely in the oven.
- Prep Time: 10 minutes
- Cook Time: 1 hour
- Category: Side Dish
- Method: Baking
- Cuisine: American
Keywords: Acorn squash recipe, caramelized onion squash, Gruyere squash bake, roasted squash, vegetarian side dish, fall recipes
