Sauté the mushrooms in 3-4 tablespoons of olive oil for 5 minutes over a high heat and, when cooked, drain and place them in a bowl. Add the onion, garlic, oregano, eggs (beaten), breadcrumbs, Gruyère cheese, yogurt and minced beef to the mushrooms. Add salt and pepper and knead the mixture to form a roll about 30 cm long. Wrap the meatloaf in the pastry sheets, according to the instructions. Bake in a preheated oven at 180°C for 45 minutes.

For making Filo Pastry Roll:
Brush the sheets with olive oil and stack them together to form layers.

Place the meatloaf along the longest side of the stack, roll once and fold the side edges inwards.

Continue until you wrap the meatloaf in a roll and brush the roll's surface with olive oil.