Rinse morels cold, drain and soak in 1/8 litre hot water. For the gratin peel the potatoes and cut them into thin slices. Bring milk, cream, salt, pepper and nutmeg to the boil with the potato slices, season if necessary. Pour the mixture into one large or two small flat gratin dishes and sprinkle with cheese. Bake in the preheated oven (electric cooker: 200 °C/ gas: level 3) for 30-35 minutes.
Season meat with salt and pepper. Place on a greased ovenproof dish and place in the oven for gratin. Bake for 15-20 minutes. Peel the carrots, first cut them into pieces of about 4 cm, then into small ellipses. Steam carrots in fat and 6 tablespoons of water for about 10 minutes. Add the frozen peas and steam for about 5 minutes. Season with salt. Take the meat out of the oven, wrap in aluminium foil and keep warm. Bring the gravy with morels, the soaking water and crème fraiche to the boil and simmer for about 10 minutes over a mild heat. Thicken with sauce thickener, bring to the boil again and season with salt and pepper.
Add the frozen peas and steam for about 5 minutes. Season with salt. Take the meat out of the oven, wrap in aluminium foil and keep warm. Bring the gravy with morels, the soaking water and crème fraiche to the boil and simmer for about 10 minutes over a mild heat. Thicken with sauce thickener, bring to the boil again and season with salt and pepper. Wash parsley, dab dry, chop finely and add to the vegetables. Cut the meat into slices and serve with morel sauce, potato gratin and vegetables