Wash the vegetables thoroughly.
Peel the potatoes and boil them until tender in lightly salted water.
Simmer the onions, carrots and cabbage in a frying pan with the addition of vegetable oil over medium heat until soft and golden brown.
Puree the boiled potatoes. Add sour cream, egg, salt and pepper to taste. Mix all ingredients until smooth.
Prepare a baking dish by greasing it with butter and filling it with breadcrumbs. Place the potato mixture in the mold and spread over all surfaces.
Fill the casserole with grated cheese and place in the oven at 180℃. Bake for 35-40 minutes until golden brown.
Cut the finished casserole into portions and place on serving plates. Top the casserole with tomato slices and fresh herbs.