1. Preheat oven to 185°C (365°F).
2. Clean and slice mushrooms. Briefly wash spinach sheets and chop them up slightly. Fry onions, garlic and thyme in heated olive oil. Add mushrooms and cook until the liquid has evaporated. Switch oven off, add salt, pepper and egg. After this has cooled down, mix with spinach and feta cheese.
3. Use a muffin baking tray and grease with butter. Cut pastry into squares of approx. 6 x 6 cm, put them into the muffin shapes and fill in. Seal pastry "muffins" well. Possibly brush the pastry parcels with egg or oil before baking.
4. Bake light brown at 185°C (365°F) for approx. 15 minutes. The baking time and temperature can vary slightly depending on the type of oven.