As in home made, from scratch, with a balloon whisk.  Something I’d never attempted before, but thought I would like to do.  I halved the recipe, because I wasn’t sure it would work, and used very mild olive oil, freshly squeezed lemon juice and the mustard in the fridge.  I was nervous, so took it very slowly.  At first, I thought it wouldn’t work, but then all of a sudden, there it was, thickening and turning into mayonnaise. Just like magic!  I took Nigel Slater’s advice to put in a bit of salt (although I suppose the mustard would have helped) and to stop when it looked okay, but I wasn’t sure I shouldn’t have stopped adding sooner.  We had it on mixed salad leaves as an accompaniment to pizza. Extremely delicious, and definitely on my special treats list.