Wash the potatoes and cook in boiling water for about 20 minutes. Peel and wash the carrots and cut them into slices. Cook carrots in little boiling salted water for 5-7 minutes. Lift out carrots with a skimmer, drain.
Cook the peas in boiling carrot water for about 3 minutes. Drain and leave to drain. Peel and finely dice onion. Heat oil in a pan, fry minced meat in it until crumbly. Add onion and herbs and fry briefly.
Add tomato paste and sweat briefly. Season with salt and pepper and add 100 ml water. Let it simmer until the water has almost evaporated. Drain potatoes, rinse with cold water and peel.
Cut the potatoes into slices. Mix peas into the minced meat and season with salt and pepper. Whisk sour cream and eggs, season with salt and nutmeg. Grease a casserole dish. Layer about 2/3 of the potatoes and carrots in the dish.
Pour with approx. 1/3 of the sand casting. Add the chopped meat mixture and press down a little. Spread the rest of the potatoes and carrots on top. Pour the rest of the icing over it. Sprinkle breadcrumbs over it. Put butter in flakes on top.
Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 40-45 minutes.