Take the dough out of the refrigerator, let it rest unopened for about 10 minutes. Clean and wash the spinach. Peel shallots and garlic and dice finely. Wash the lemon and finely grate the peel. Wash parsley, shake dry and chop finely.
Melt the butter. 6 Grease the hollows of a muffin tray (not adjacent) or cupcake forms with butter.
Heat the oil in a pan with a lid. Sauté shallots and garlic in it. Add the spinach and cover and let it collapse. Remove from the heat, squeeze a little if necessary and let it drip off. Crumble the feta and mix with the ricotta.
Stir both with lemon zest and parsley into the spinach. Whisk eggs and nutmeg and stir into the spinach. Season with salt and pepper.
Remove 3 pastry sheets from the package and separate them. (Wrap the rest of the dough sheets well and use them for other purposes.) Cut the dough sheets in half lengthwise and crosswise to make 12 squares.
Brush thinly with butter. Place 2 dough squares on top of each other in the greased troughs.
Sprinkle 1 teaspoon of breadcrumbs into each. Spread the spinach filling evenly. Whip the edges of the dough over it. Bake in the preheated oven (electric range: 175 °C/circulating air: 150 °C/gas: level 3) on the lowest rack for approx. 20 minutes.
Serve hot.