Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.

In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add sliced yellow onions and sauté for about 15-20 minutes until golden brown.

In a separate skillet, add the remaining tablespoon of olive oil and cook cubed butternut squash for about 10-15 minutes until tender.

Transfer caramelized onions and cooked squash to a mixing bowl. Fold in fresh thyme, salt, and pepper.

Unroll chilled puff pastry onto the prepared baking sheet. Spread the filling evenly over it and crumble goat cheese on top.

Bake for 25-30 minutes until the pastry is puffed and golden brown.