White Asparagus with Cream Sauce ('Spargel mit heller Soße')

Prepare the white sauce:

Add your asparagus peel and trimmings into a saucepan and cover with about 3 cups of water so that they are fully submerged. Bring the water to a boil and simmer the asparagus broth for 15-20 minutes. Strain and set aside.

Heat the butter in a saucepan over medium heat. Add the flour and sweat the butter-flour mixture ('roux') for 2-3 minutes or until it starts to smell nutty but is still pale in color. Then, whisk in the asparagus broth, bit by bit, to prevent the sauce from turning lumpy. Add 1 teaspoon of sugar and let the sauce simmer over the lowest possible heat for at least 10 minutes to cook out the raw flour taste.

Cook the asparagus:

While the sauce simmers, cook the asparagus in salted boiling water for about 10-15 minutes. It should be tender throughout but still retain a little bite. The texture of properly cooked asparagus is almost meat-like with a buttery-soft asparagus tip.

Finish the sauce:

In a small bowl, whisk together the egg yolk and heavy cream. Take the sauce off the heat and whisk in the cream mixture. Don't bring it up to a boil again as the egg might curdle otherwise. Season the sauce to taste with lemon juice, nutmeg, and salt. If the sauce is too thick or thin to your liking you can adjust the texture by either adding more liquid or by thickening the sauce slightly more with cornstarch. Be careful not to over thicken it. The sauce should be light and silky.

Serve the dish:

Serve the asparagus with a generous amount of sauce and sprinkle with chervil leaves. Asparagus is usually eaten with torn pancakes, regular pancakes, or boiled potatoes on the side.