Peel and finely chop the onion. Wash thyme and chop finely. Melt the fat. Sauté onion in it. Add flour and sauté. Add stock and cream while stirring constantly, bring to the boil.
Season to taste with salt, pepper, nutmeg and thyme. Clean and wash the cabbage. Remove the leaves from the stalk bit by bit. Peel and wash the potatoes and cut them into thin slices. Fill prepared ingredients and ham in layers with the sauce in a suitable casserole dish.
End with gravy. Sprinkle this with parmesan. Cook in the preheated oven (electric cooker: 175 °C/ gas: level 2) for 45-50 minutes. Serve garnished with fresh herbs.