For 6 pieces :
1. Preheat oven at 180°C/350°F.
2. Chop garlic very finely.
3. Chop spinach in big chunks.
4. In a pan, add olive oil and fry spinach and garlic for about 7 minutes or until all the liquid has evaporated.
5. Season spinach with salt and pepper and mix well.
6. Cut 6 equal squares in the puff pastry sheet.
7. On each square, add a tablespoon of spinach and crumble some Coeur de Chèvre on top, leaving space on the sides.
8. Fold the corner onto the middle of the square and pinch well to set the folding.
9. Brush the squares with egg yolk.
10. Bake for 10 to 15 minutes, the squares must be golden and crispy.