Mix the flour with the dry yeast. Carefully heat the milk, margarine and a pinch of sugar. Put the flour, 1/2 teaspoon salt and 1 egg in a mixing bowl. Pour in the yeast milk and make a smooth dough. Let rise for about 30 minutes.
Meanwhile, defrost the spinach in the saucepan. Mix the finely chopped onion with the spinach and squeeze in the clove of garlic. Put the diced sheep`s cheese in a bowl and season with salt and pepper.
Preheat the oven to 200 ° C top / bottom heat. Shape the dough into 2 balls, roll them out into an oval shape and place on 1 baking sheet.
Put half of the cheese and spinach mixture in the middle of each dough. Fold the edges of the dough inwards. Do not completely cover the filling.
Whisk an egg yolk with 1 tablespoon of milk and brush the dough with it. Beat one egg and mix with the rest of the egg white. Put the mixed egg over the filling, if necessary spread it with a pastry brush.
Bake the pide in the oven for about 20 minutes, until the sheep`s cheese turns brown.