Pour the stock into a pot and bring to the boil. Add rice and cook over low heat for about 20 minutes. Drain on a sieve. Peel and finely chop the onion. Heat 1 tablespoon of oil in a pan and sauté the onion in it.
Mix rice, onion, eggs and flour together. Season with salt and pepper. Heat the remaining fat. Place a heaped tablespoon of the rice mixture in each pan, press flat and fry on both sides for 3-4 minutes at medium heat until golden brown.
Mix quark and cream. Season to taste with horseradish, salt and pepper. Wash the chives, dab dry and cut into small rolls. Clean, wash and dry radishes and cut into sticks.
Fold them both under the curd. Arrange the rice fritters, curd cheese and salmon on plates and serve garnished with salad, chervil and radishes as desired.