2 sheets puff pastry
2 tablespoons unsalted butter
2 tablespoons all-purpose flour
1 cup (240ml) warm milk
1 pinch of salt
Freshly cracked pepper, to taste
Ground nutmeg (optional)
1/2 lb (220g) cooked ham, diced
2 cups fresh spinach, rinsed and chopped
1 cup Swiss cheese, grated

Cut the puff pastry sheets into 5-inch (13cm) squares. Set aside in the refrigerator. Pre-heat your oven to 400°F(200°C). For the béchamel sauce: Melt butter over medium heat in a saucepan. Add flour and salt; cook, stirring frequently, until the mixture becomes pale golden with a slightly nutty aroma. Pour warm milk in 2 steps, stirring constantly with wooden spoon and whisk until smooth. Cook the mixture, stirring constantly along the bottom of the saucepan, until boiling, about 7 minutes. Reduce heat to low. Simmer gently until sauce thickens, about 10 minutes. If you still have lumps, use your immersion blender. Stir in spinach and cook for 1 minute. Add ham and cheese and stir well. Set aside. Arrange the puff pastry squares on a baking sheet lined with parchment paper. Dollop 1 or 2 tablespoons of the béchamel mixture, top with grated cheese and close the pockets by folding the corners on top. Make an egg wash using an egg and 1 coffee spoon of cold water. Brush the puff pastry and bake in the oven for 20 minutes, until puffed and golden. Serve immediately with a crisp salad.