White asparagus with hollandaise sauce

Rinse the asparagus and lay one spear flat on a board, supporting the delicate tip. Peel the skin from about 2–3 cm below the tip all the way to the end, rotating the spear. Peel the lower half especially carefully. Cut off the tough ends, usually about 2–4 cm. Leave the tips unpeeled. From 2 kg whole asparagus, expect roughly 1.4 kg edible spears; waste depends on freshness and thickness. Set peelings and ends aside outside this dish.

Melt all 150 g butter in a small saucepan over the lowest heat, without browning. Take off the heat and leave for a few minutes so it stays liquid and distinctly warm but not scalding. Do not clarify, do not skim off foam and do not pour off the milk solids; gently stir before pouring it in. Heat about 2–3 cm water in a second saucepan. Choose a metal bowl that rests firmly on the rim with its bottom above the water. The water should steam only gently, without boiling vigorously.

Bring about 2.5 l water with 8 g salt to a boil in a wide pot. Arrange the peeled asparagus so it is submerged and fits without breaking; if necessary, cook in two batches in the same water. Reduce the heat to a gentle simmer and cook for about 10–15 minutes, depending on thickness. A knife tip should enter the lower part of a spear with slight resistance, while the asparagus keeps its shape. Start whisking the sauce while it cooks. Lift out the cooked spears with a wide slotted spoon and drain well; exclude the water from the servings.

Weigh 54 g yolks into the fitted bowl. Add the 20 g lemon juice, 20 g of the prepared sauce water and 1 g salt. Whisk, then set the bowl over gently steaming water. Whisk without stopping for about 5–7 minutes, until noticeably paler, foamy and thickened, with the whisk leaving a briefly visible trail. The bowl's bottom must not touch the water. If the steam becomes vigorous or the yolks start sticking, briefly remove the bowl and reduce the heat; do not let the yolks scramble.

Take the bowl off the saucepan and set it on a rolled-up kitchen towel. Whisking constantly, add the warm melted butter a few drops at a time at first, then in a very thin stream once the sauce starts thickening noticeably. Pour in all 150 g with the milk solids, scraping the saucepan with a spatula. Finally, stir in the remaining 10 g water. The sauce should be smooth and fluffy, flowing from a spoon in a broad ribbon. Do not boil it and do not place it directly on a burner. If needed, warm the bowl briefly over gentle steam, stirring constantly.

Divide all the well-drained hot asparagus among four warmed plates. Point the tips in the same direction and pour all the prepared sauce over the spears, dividing it evenly into four servings. Do not add separate butter, herbs or lemon slices. Serve immediately; do not prepare the sauce many hours ahead and do not leave it warm for a long time. Quickly cool any leftover asparagus on its own, seal in a container and refrigerate until the next day. It is best to make only enough sauce for the current serving.