Peel and core the cucumber and cut into small cubes. Sprinkle with salt and let stand for about ten minutes and then pour off the cucumber water. Peel and core the apples, cut into cubes and drizzle with the lemon juice. Cut the radishes into fine cubes or slices.
Mix everything with the quark, season with salt and pepper and sprinkle with the parsley.
The salad goes well with grilled food and is the perfect bring-along salad.