Sauté the finely chopped onions with 2-3 finely chopped tomatoes in some of the butter. Add the remaining coarsely chopped tomatoes and the flour.
Stir well briefly and transfer to a pre-greased baking dish, along with the crumbled feta cheese and beaten with milk eggs. Salt the dish to taste and put it to bake in a moderately heated oven.
Finally, add the remaining butter and finely chopped parsley.