Clean the salad, remove the leaves from the stalk and wash. Spin dry lettuce and pluck from the leaf panicles. For the salad dressing mix sour cream, milk and lemon. Season with sugar and 1 pinch of salt.
Clean and clean the mushrooms and cut them into slices. Wash the meat, dab dry and season with salt and pepper. Heat oil in a large pan. Fry the meat for about 6 minutes while turning it.
Meanwhile, heat the fat in a second pan, add the spaetzle and fry for 5-10 minutes, turning. Season to taste with salt and nutmeg. Remove meat from the pan and keep warm. Fry the mushrooms in the hot frying fat for about 4 minutes.
Season with salt and pepper. Add cream, bring to the boil and boil down for about 1 minute. Arrange salad in bowls and drizzle with dressing. Arrange meat, mushroom sauce and spaetzle on plates. Sprinkle with fried onions.