Preheat oven to 200°.

Wash well onions and mushrooms. Chop them and prepare to fry in separeted pans on olive oil. Keep frying onions for at least 20 min, stiring permanently and adding salt and pepper to taste, until they will release the juice and become soft. Fry mushrooms the same way until cooked. Mix together onion and mushrooms. Add dry herbs, e.g. thyme.

Place a paper sheet in a baking pan, put bottom slice of dough. Spoon filling onto dough, leaving a 1-inch border around the edge. Place another slice of dough over filling. Pinch edges to seal. Make a cut on top of dough to allow steam to escape. Brush with olive oil.

Bake at 200° for 30 minutes, until golden brown. Cool down.