Clean, wash and halve the cabbage and cut into 8 slices with the stalk. Heat 1 tablespoon of oil in a large frying pan. Leave the ham cubes in it while turning them until crispy, take them out. In the meantime peel and finely dice the onion.
Put 3 tablespoons of oil into the pan and fry the cabbage slices in it in 2 portions while turning, season with salt and pepper, remove. Lightly sauté the onion in the frying fat. Dust with curry, sauté, dust with flour, sauté, gradually deglaze with stock and cream. Bring to the boil, simmer for 1-2 minutes. Season to taste with salt, pepper and sugar.
Put the cabbage slices into an ovenproof casserole dish, pour the sauce evenly over them. Sprinkle with cheese and ham. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for 15-18 minutes.
Wash parsley, shake dry and cut finely, except for 1 leaf for garnishing. Remove the casserole from the oven, sprinkle with parsley and garnish. Bread tastes good with it.