If you want to know more details about how to cook asparagus, please look at the following link. It is very informative.
White asparagus is greatly prized in Germany, Holland, Italy and France and most of Europe but not very common in the US. White asparagus is actually asparagus that are grown under mounds of earth to protect its pale stalks from the sunlight inspired chlorophyll that would otherwise turn them green. Underground, the asparagus often grow fibrous and woody stems so they need a long cooking time compared to green asparagus and their skins tend to toughen. This is the reason that white asparagus is always peeled before cooking. The overall cooking time depends on the age and thickness of its stalks, but it is always considerably longer than the green variety – particularly since, white asparagus is never eaten crisp.
This recipe comes from the Auberge de Noves near Avignon.
1 cup dry white wine
1/3 cup white wine or champagne vinegar
2 egg yolks, lightly beaten
1/3 cup extra-virgin olive oil
Salt and freshly ground black pepper
500 g / 1 lb white asparagus, peeled
Combine wine and vinegar in a saucepan over medium high heat
Bring to just under the boiling point
Continue cooking until the liquid is reduced by 3/4, about 15 minutes
Allow to cool
Transfer to the top of a double boiler or a bowl over a pan of simmering water
Whisk egg yolks into the wine reduction
Set over simmering water and cook, whisking continuously, until yolks thicken enough to fall into thin ribbons when whisk is lifted from pan
Off the heat, whisk in the olive oil, slowly
Thin, if necessary, with 1 to 2 tablespoons water
Season to taste and set aside
Place the asparagus in cold water and bring to a simmer over medium high heat
Reduce heat, cover and cook until asparagus is tender, about 15 to 30 minutes
Transfer asparagus to a platter and spoon some sauce over