Steps
1. Preheat oven to 200°C (400°F).
2. Heat olive oil in a skillet over medium heat.
3. Add sliced onions and minced garlic, cook slowly until golden and caramelized, about 15 minutes.
4. Stir in balsamic vinegar, thyme, salt, and pepper; cook for another 2 minutes.
5. Roll out puff pastry on a baking sheet lined with parchment paper.
6. Spread caramelized onions evenly over the pastry, leaving a 1-inch border.
7. Crumble goat cheese on top of the onions.
8. Fold the edges of the pastry slightly over the filling.
9. Bake in the oven for 20-25 minutes or until pastry is golden and crisp.
10. Let cool slightly before serving.