Peel the asparagus stalks, cut into bite-sized pieces and cook with a little salt, a pinch of sugar and the butter until al dente.
Halve the eggs, whisk the yolks with the mustard, oil and vinegar and season with salt and pepper. The sauce should be quite creamy, not too runny.
Cut the ham into cubes, chop the chives and egg whites and add to the sauce. Add the cooked asparagus pieces while still warm and serve the salad warm to lukewarm.