Begin by beating the egg yolk with 1 tablespoon of white wine vinegar and 1 tablespoon of water or lemon juice. While beating (a mixer or blender makes this much easier; I use a small food processor), slowly pour in the oil, always making sure that the amount of free (unabsorbed) oil is a fraction of the amount of egg yolk or emulsified mayonnaise. If the mayonnaise gets very thick and the oil is not mixing in properly, add water a teaspoon at a time to help it.
If you are concerned about salmonella in raw eggs, there are two other ways to construct a suitable starter to add the oil to.
The first is to almost-cook the egg yolk with the aid of a microwave oven and three clean forks or small whisks. Beat together, in a microwave-safe bowl, the egg yolk, vinegar and lemon juice or water. Remember that the tool you use to beat this is "contaminated" and must no be re-used from this point. Put the mixture in the microwave on high and bring it to a boil. After 8-10 seconds of boiling, stop the oven and quickly beat the mixture thoroughly with a fresh clean fork or whisk, to make sure no cold spots remain. Place back in the microwave and repeat, beating at the end with a third clean fork or whisk.
The second is to begin with a relatively small amount of store bought mayonnaise (3 tbsp) in place of the egg yolk and vinegar and beat in a few tablespoons of water before adding the oil. This actually works with brands that do not use gelatin or artificial thickeners, although the result is a little thin. (There is about 1/3 of an egg yolk in a quart of commercial mayonnaise, and this stretches it even more.)
In eiher case, proceed to slowly add oil, as above. If the mayonnaise "breaks" into curdled egg and runny oil, don't panic-you have not wasted all that expensive oil. You either added the oil too fast or didn't have enough water. Set the broken mixture aside, and start over with a teaspoon or two of the broken mayonnaise (particularly the curdled egg) and a tablespoon of water, which should be easy to beat into a smooth but thin mayonnaise, then slowly add the broken mixture back in as if it were oil.
Chill the mayonnaise immediately and do not let any of this product remain at room temperature for longer than it takes to eat it.
Ready for some quick and luscious recipes from Giovanni's? Try 5-Minute Polenta Melts, Panettone French Toast or Giovanni's Rich Caesar Salad.
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