I separated my yolks & whites, and put the yolks in a little bowl and then did it exactly as I would if it was an entire egg -- few drops of formula in instead of milk, mix it around, and pour into the frying pan. Takes hardly any time at all, and I always tried to keep it to one corner of the pan so that it didn't spread out too much and go bitty. It seems weird doing one egg yolk, but in practise it is no different than doing 4 whole eggs!