450g/ 1 lb Asparagus, trimmed
1 tbsp butter
1 tbsp vinegar
salt and freshly grounded black pepper
50g Parmesan cheese, grated
Cook the asparagus in boiling salted water for about 8 to 10 minutes until tender. Drain and cut into even-sized lengths and place on a warmed serving plate in the shape of pyramid. Place the butter in a saucepan and beat the egg yolks.
Add the vinegar and season with salt and pepper. Cook until thickened, stirring all the time. Do not allow to boil. Pour over the Asparagus, Sprinkle with the Parmesan cheese and serve at once.