Clean and wash the spring onions and cut into fine rings. Peel and roughly grate the potatoes, mix with onions, egg and flour. Season with salt and pepper.
Heat oil in a pan. Put the roasted dough in a pan, smooth it out and bake the underside for 5-7 minutes until golden brown. Let the hash browns slide onto a flat top lid, turn the lid with the help of the lid and continue frying for another 5-7 minutes.
Roughly chop the herbs. Mix the quark, sour cream, mineral water and chopped herbs, season with salt and pepper. Serve the rösti with quark and salmon. Serve garnished with dill.