# Ingredients:
→ 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
05 - 2 large yellow onions, thinly sliced
06 - 2 tablespoons unsalted butter
07 - 1 tablespoon olive oil
08 - 1/2 teaspoon kosher salt
09 - 1/2 teaspoon granulated sugar
10 - 2 teaspoons balsamic vinegar
11 - 2 tablespoons fresh thyme leaves
→ Filling and Garnish
12 - 1 1/2 cups Gruyere cheese, grated
13 - 1/4 cup chopped fresh parsley (optional)
14 - Additional fresh thyme leaves for garnish
# Instructions:
01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Brush cut sides of acorn squash with olive oil, season with kosher salt and black pepper. Place cut side down on prepared baking sheet and roast for 35 to 40 minutes until fork-tender.
03 - Heat butter and olive oil in a large skillet over medium-low heat. Add sliced onions and kosher salt. Cook, stirring occasionally, for 30 to 35 minutes until onions are deeply golden and soft, adding sugar halfway through to promote caramelization.
04 - Stir in balsamic vinegar and fresh thyme. Cook for an additional 2 minutes, then remove from heat.
05 - Remove squash from oven, turn cut side up. Reduce oven temperature to 375°F.
06 - Divide caramelized onions evenly among squash cavities. Top each half with grated Gruyere cheese.
07 - Return stuffed squash to oven and bake for 15 to 20 minutes until cheese is melted and golden at edges.
08 - Remove from oven and garnish with fresh parsley and additional thyme leaves before serving.
