3. For the vinaigrette, mix the egg yolks with mustard, lime juice and shredded peel in a blender at lowest speed. Add ginger syrup, grapefruit juice and shredded peel. Put the blender on mid-speed and add the grape seed oil little by little until the vinaigrette binds. Salt and pepper to taste. Now, pour the vinaigrette in a clean, dry bottle. If you store it in a fridge, it will keep well for three days.