method
1. Clean the asparagus and boil in salted water for 18 - 20 minutes.
2. Drain and cut into even sized lengths and place on a warmed serving plate in the shape of a pyramid.
3. Place the butter in a saucepan and beat in the two egg yolks.
4. Add the vinegar and season with salt and pepper. Cook until thickened, stirring all the time.
5. Pour over the sauce, sprinkle with the Parmesan cheese and serve at once.