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

2. In a large skillet, heat butter and olive oil over medium heat.

3. Add sliced onions and cook slowly, stirring often, for 20–25 minutes until golden and caramelized.

4. Stir in balsamic vinegar, brown sugar, salt, and pepper; cook another 2 minutes, then set aside.

5. In a small bowl, mix goat cheese, cream cheese (if using), and thyme until smooth.

6. Unroll puff pastry and cut into 6–8 squares. Score a 1/2-inch border around each square with a knife (don’t cut all the way through).

7. Spread a small spoonful of the cheese mixture in the center of each square.

8. Top with caramelized onions and brush pastry edges with beaten egg.

9. Bake for 15–18 minutes, until pastry is puffed and golden.

10. Drizzle lightly with honey and garnish with fresh thyme before serving.