Peel and chop the onion. Clean, peel and wash the carrots and turnips. Cut carrots into slices and turnips into cubes. Heat 1 tablespoon of oil in a saucepan, fry the onion in it.
Add the carrots and turnips and steam briefly. Dust with flour and sauté briefly. Gradually add 250 ml water and cream, stirring continuously. Bring to the boil, stir in the stock and simmer for 5 minutes over a mild heat.
Wash the steaks, pat dry. Heat 2 tablespoons of oil in a pan, fry the steaks on each side, remove. Season meat and vegetables with salt and pepper. Put the vegetables and steaks in an ovenproof dish (approx. 1.5 litres capacity), sprinkle with cheese.
Bake in the preheated oven (electric cooker: 200 °C/ convection oven: not suitable/ gas: level 3) for 10-15 minutes. Wash parsley, dab dry and chop finely. Sprinkle over the casserole.