Wash and peel the asparagus and cut off the woody ends. Brush the potatoes and wash them thoroughly. Cook potatoes in boiling water for about 20 minutes. Put asparagus in boiling salted water with sugar.
Bring to the boil and cook over medium heat for about 15 minutes. Wash parsley, shake dry and chop finely. Wash the meat, dab dry. Heat oil in a pan and fry meat in it for 1-2 minutes on each side.
Season with salt and pepper. In the meantime melt butter and stir in truffle butter. Drain potatoes and sprinkle with parsley. Lift the asparagus out of the water and let it drip off. Arrange asparagus with butter mixture, meat and parsley potatoes on plates.
Garnish with parsley.