Steps
1. Preheat the oven to 200°C (400°F).
2. Heat olive oil in a pan over medium heat. Add the sliced onions and a pinch of salt.
3. Cook onions slowly, stirring occasionally, until golden brown and caramelized (about 20 minutes).
4. Stir in honey (if using) and thyme leaves, cook for another minute, then remove from heat.
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 around the edges.
7. Crumble goat cheese on top of the onions.
8. Fold the edges of the pastry slightly over the filling to create a rustic border.
9. Bake in the preheated oven for 15-20 minutes, or until the pastry is golden and puffed.
10. Remove from oven, let cool slightly, slice, and serve warm.