Fresh Asparagus with Foaming Hollandaise

You can make the sauce at any time: we have tried it chilled overnight in the refrigerator, which makes a nice contrast with the hot asparagus, or you can serve it warm, or even at room temperature.

Begin by placing the egg yolks in a food processor or blender together with some salt, switch on and blend them thoroughly. In a small saucepan heat the lemon juice and vinegar till the mixture simmers, then switch the processor on again and pour the hot liquid on to the egg yolks in a steady stream. Switch off, then in the same saucepan melt the butter – not too fiercely: it mustn't brown. When it is liquid and foaming, switch on the processor once more and pour in the butter, again in a steady, thin stream, until it is all incorporated and the sauce has thickened.

Next, in a small bowl, whisk the egg whites until they form soft peaks and then fold the sauce, a tablespoon at a time, into the egg whites and taste to check the seasoning. When you've done that, it's ready to serve or it can be left till later.

To cook the asparagus: take each stalk in both hands and bend and snap off the woody end, then trim with a knife to make it neater. Lay the asparagus stalks on an opened fan steamer (or an ordinary steamer will do) – they can be piled one on top of the other. Season with salt, place them in a frying pan or saucepan, pour in about 1 inch (2.5 cm) of boiling water from the kettle, then put a lid on and steam for 4-6 minutes.

Serve the hot asparagus with some sauce poured over the tips, and don't forget to have finger bowls and napkins at the ready.