Rinse upper leg cold and pat dry. Rub with salt and cayenne pepper. Heat 4 tablespoons of oil in a frying pan, fry the leg in it thoroughly all around. Pour on 1/4 litre of water, cover and stew for about 1 1/2 hours.
In the meantime, pour hot water over Mu Err mushrooms and let them swell for 20 minutes. Clean, wash and possibly halve the sugar snap peas. Blanch briefly in boiling salted water. Drain and rinse with cold water.
Peel the carrots, carve them lengthwise and cut them into flowers. Rinse sprouts cold and let them drip off. Drain pineapple rings, catching the juice. Cut the pineapple into pieces. Peel garlic and ginger and chop finely.
Mix ketchup, 4 tablespoons of pineapple juice and vinegar. Season with salt, cayenne pepper and five-spice mixture. Drain mushrooms and rinse in a sieve. Heat the remaining oil in a pan. Fry the carrots for about 5 minutes.
Add sugar snap peas, mushrooms, pineapple and sprouts and cook briefly. Remove the roast from the roaster. Add frying stock to the ketchup sauce, pour over the vegetables and bring to the boil again. Arrange the roast with the vegetables on a plate.
Garnish with Asian garlic as desired. Rice tastes good with it.