method
1. Beat the egg yolks lightly. Add the mustard, salt and vinegar or lemon juice and mix well together.
2. Whisking all the time, add the oil drop by drop: a bottle with a notched cork will restrict the flow.
3. Carry on adding oil and whisking all the time until the mixture thickens. Then mix in a steady trickle of oil.
4. Keep beating. If mayonnaise becomes too thick, thin it down a little with lemon juice or a little vinegar.
5. The finished mayonnaise should hold its shape. Taste for seasoning and add a little pepper if desired.
