1.Remove the skin of tomatoes and cut the onions.
2.Make a mixture of onions, tomatoes, parsley, cheese, salt and pepper.
3.Preheat the oven to 400 F
4.In a fry pan, heat butter and saute the fish in it until brown.
5.Take a soaked Romertopf, place a fish layer on it and add a sprinkling of lemon juice to it.
6.Put the onion mixture on the fish.
7.Place the fish again on the top and add lemon juice.
8.Put the lid on and cook in heated oven for 45 minutes.
9.Once done, make a mixture of flour and sour cream and add to the dish.
10.Cook further until the fish browns form the top.
11.Serve warm with rice or French fried potatoes.