1. Beat egg yolks in a bowl with powdered sugar. Whip with a whisk. Whip until the egg yolks expand in volume, lighten in color and become thick. At this point, add a little salad oil and beat with a whisk so that the oil and egg yolks are fully integrated.

2. Continue to add oil in small amounts. Make sure you don't add too much oil at a time, stirring with a whisk as you go. As the oil is added little by little, the egg yolks will become thicker and thicker instead of thinner. Until you add 67 grams of salad oil, the sauce is thicker and darker.

3. At this point, because the sauce is too thick, it is not good to mix, add 1 small t of white vinegar (do not add too much), mix well. After adding the vinegar, the sauce in the bowl will become thinner. At this time, we repeat the process of adding oil and stirring a small number of times to make it thicker.

4. Continue to add 1 small t of white vinegar, stirring, thinning.

5. Add another small amount of oil several times, mix well and thicken.

6. Repeat adding the white vinegar and oil until all the ingredients are added. Once all the mixing is done, the salad dressing is ready.