Wash and boil the potatoes. Wash herbs, pluck and chop separately. Put some parsley aside. Mix the rest of the parsley, half of the lemon balm, quark, sour cream and milk. Season to taste with salt and pepper.
Peel and chop the garlic. Wash lemon, grate peel. Mix both with the rest of the lemon balm. Wash salmon, dab dry and cut into 4 pieces. Put 1 piece of salmon in the middle of a sheet of paper.
Spread 1 teaspoon each of oil and lemon mixture on top. Season with salt and pepper.
Fold the paper sides upwards and tie up with kitchen string. Place the parcel on the baking tray. Bake in the preheated oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3) for 15-20 minutes.
Drain and peel the potatoes. Melt the fat, toss the potatoes in it. Season with salt, sprinkle the rest of the parsley over it. Arrange everything together with fish in paper.