Wash the potatoes and cook in boiling water for about 20 minutes. In the meantime clean, peel and slice carrots diagonally. Clean and wash broccoli and cut into small florets.
Bring the stock to the boil and steam the vegetables for about 4 minutes. Pour the vegetables onto a sieve and collect the broth. Wash the chicken fillets, dab dry and cut into 4 equal pieces. Heat the oil in a pan and fry the fillets on both sides, turning them over.
Season with salt and pepper. Drain potatoes, rinse with cold water, peel and slice. Alternate with the vegetables in a greased casserole dish. Place the chicken fillets on the vegetables.
Heat the fat in a pot and sauté the flour in it. Add stock and milk while stirring, bring to the boil and simmer for 4-5 minutes. Melt cheese in the sauce and season with salt, pepper and nutmeg.
Pour sauce over vegetables and meat and bake in the preheated oven (electric: 200 °C/ gas: level 3) for 25-30 minutes. Serve garnished with parsley.