Mix the first six ingredients together with a wire whisk in a bowl until the mixture is uniform and beginning to thicken.
Add the oil drop by drop while continuing to whisk. Keep that up until you notice a change in texture of the mixture--it starts to get a little stiff. Usually you see this when about a third of the oil is in there.
At that point, you can add the oil in a thin stream, continuing to whisk. If at any point it looks as if the oil isn't being incorporated, stop adding it until your whisking gets it in there. Keep going until all the oil is used.
