Put flour and salt on a baking board. Press a depression into it. Spread cold flakes of fat on the edge of the flour and put three tablespoons of ice water in the middle. Chop thoroughly with a wide knife, knead quickly with cool hands to a smooth dough and cover and leave in a cool place for one hour. Peel and finely dice the onion.
Heat the oil in a pan, fry the onion in it until transparent, dust with cayenne pepper. Clean, wash and cut the leek into slices. Coarsely grate the cheese. Mix the prepared ingredients. Mix eggs, milk, flour and cream. Season to taste with salt, pepper and nutmeg. Roll out the dough on a floured work surface to a thickness of three millimetres. Grease a tart or dough mould (22 centimetres in diameter) and line with the dough. Prick the base several times with a fork and pre-bake for ten minutes in a preheated oven (electric range: 200 °C/ gas: level 3). Then spread the vegetable-cheese mixture on top and pour egg milk over it.
Roll out the dough on a floured work surface to a thickness of three millimetres. Grease a tart or dough mould (22 centimetres in diameter) and line with the dough. Prick the base several times with a fork and pre-bake for ten minutes in a preheated oven (electric range: 200 °C/ gas: level 3). Then spread the vegetable-cheese mixture on top and pour egg milk over it. Bake for another 30 minutes at the same temperature. After ten minutes sprinkle with sunflower seeds. Results in twelve pieces
Preparation time approx. 1 hour (without waiting time)