Mix the quark, 1 egg, oil, milk, flour, sugar, baking powder and a pinch of salt to form a quark-oil batter. Roll out the dough on a parchment-lined baking sheet.
Peel the potatoes and cook them in the milk until soft.
Mix the sour cream with the second egg. Add the milk and potato mixture. Cut the spring onions and leek into thin slices and wash. Drain well and mix with the potato sour cream. Add the herbs for the green sauce and stir in well. Season with salt, pepper and nutmeg.
Spread the mixture on the dough. Dice the lean bacon, toss in breadcrumbs and sprinkle over it.