Cut approx. 5 thin slices from the cucumber. Roughly grate the rest and drain well on kitchen paper. Finely dice the onion. Mix quark with mineral water until smooth. Stir in the grated cucumber and diced onion. Season with salt and pepper
Fry the giros in a hot pan for about 4 minutes while turning. Cover a slice of toast with slices of cucumber. Spread the giros, cucumber curd and parsley on top. Cover with the second slice of toast