Boil the spaetzle in salted water, drain and set aside.
Meanwhile, cut the chicken breasts into fine strips and cut the onions into rings. Briefly marinate the meat and onions with oil and spices. In the meantime, cut the peppers into pieces. Fry the meat with the onions in a non-stick frying pan, briefly add the paprika, season with salt, pepper and paprika.
Put the spaetzle in a greased baking dish, spread the meat with the vegetables on top. Mix the cream (or milk) with the sour cream, season with salt and pepper, pour over the casserole. Finally, sprinkle the cheese on top and bake at 175 degrees (preheated) for about 10-15 minutes until golden brown.