In a sauté pan, heat the oil over medium high heat. Add the shallot and sauté until soft, about 1 minute. Add the garlic and sauté for 30 second.

Stir in the spinach. Add ¼ tsp salt and cook for 2 minutes or until most of the water has evaporated and the spinach has completely wilted. Add the dill and stir to combine. Season with salt and pepper to taste. Remove the pan from the heat and then set aside.

In a medium bowl, combine the cream cheese and feta cheese. Stir in the spinach mixture. Add the egg yolk and stir to combine. Set aside.

On a lightly floured surface, roll out pastry into 12-inch square. Cut the dough into 3 inch squares and then place on a parchment lined baking sheet. Spoon about 1 tablespoon of the spinach filling on the center of the pastry squares.

Brush two connecting edges of the pastry with the beaten egg and then seal by pressing them tightly. Place uncovered, in the fridge for 10 minutes.

Preheat the oven to 400 degree F.

Remove the pastry from the fridge and then brush all surfaces with beaten egg. Bake for 20 minutes or until golden brown and puff, rotating the pan halfway through. Transfer spinach puffs on a wire rack for 10 minutes to cool.