Rinse and peel the white asparagus, avoiding the tips.

Hold the asparagus with both hands at either end and snap. If there are "strings" at the break, peel a bit more. Discard the short end.

Place the white asparagus in a steamer basket and set the basket in a pot with water. Bring to a boil and steam the asparagus for 5 minutes.

Fill a pot with water and add vinegar. Bring to a boil, but do not let it come to a rolling boil.

Crack an egg into a cup or small bowl.

Stir the water to create a whirlpool, then gently pour the egg in.

Let it poach for about 2.5 minutes.

Transfer the egg to a bowl of cold water.

Repeat the process with the next egg.

This is one of the great French classics of butter-based sauces.

Take all the sauce ingredients out of the fridge in good time. The temperature differences should be as small as possible - it's crucial for the success of your sauce.

Use a heavy-bottomed pot and clarify the butter over low heat.

Remove from the heat and pour the butter into a pitcher or measuring cup. Let it settle and remove the whey (the white foam) with a spoon. It's okay if you don't get all the whey out.

Let the butter cool to room temperature - this usually takes about 20 minutes.

Take another heavy-bottomed pot and turn on the lowest heat on the stove.

Whisk the white wine with egg yolks and lemon juice in the pot. This can be done over a water bath, as it's easier to manage (but it's not necessary).

Continue until the mixture has reached a good thickness, similar to eggnog.

Slowly add a bit of butter while whisking vigorously. The sauce will gradually thicken.

Season to taste with salt, pepper, and possibly more lemon juice.

The sauce can be kept warm over a water bath if it’s not served immediately - but make sure it doesn't get too hot. Similarly, the sauce will separate if it gets too cold and you continue to stir it.