season the egg yolks in a baking bowl with salt and pepper and whisk until the egg yolks become lighter. To do this, use either the whisk or electric hand whisk (low speed).
Add the oil a drop at a time, beating continuously. When the sauce begins to thicken, whisk in the remaining oil in a thin stream. Stir the stiff mayo with juice of one lemon or vinegar, if desired.
If you want the mayo to be even stiffer, you can add a little more oil. If it is too firm, you can dilute it with 1 to 2 teaspoons of lemon juice or lukewarm water.
Lemon juice makes the mayo lighter.
Season the finished mayo.
Additional seasoning: 1 clove of garlic or 1 tsp of hot mustard.