Steps
1. Preheat your oven to 400°F (200°C).
2. Slice the onion thinly.
3. In a skillet, heat olive oil over medium heat. Add the sliced onions and a pinch of salt, cooking until they are soft and caramelized, about 15 minutes.
4. Stir in the balsamic vinegar and cook for another minute. Remove from heat and let cool slightly.
5. Roll out the puff pastry on a baking sheet lined with parchment paper.
6. Spread the caramelized onions evenly over the pastry, leaving a small border.
7. Crumble the goat cheese on top of the onions.
8. Bake in the preheated oven for 20-25 minutes or until the pastry is golden brown.
9. Remove from the oven and garnish with fresh thyme before serving.