Wash and peel the vegetables. Cook the tagliatelle in salted boiling water, and set aside. Lightly salt the carp filets, and set aside. In a saucepan, heat some oil, cook the onions, add the mushrooms. After all of the liquid from the mushrooms cooks away, sprinkle the flour and paprika into the pan. Add 200 ml of water and salt. Bring to a boil and add the sour cream / crème fraîche (tejföl), peppers, tomato and the tagliatelle. Meanwhile, heat some oil in a frying pan and sauté the carp filets, starting with the skin side, until they are crunchy. Flip them over and cook on the other side for about two minutes. Serve with the mushroom tagliatelle.