first heat the oil (a bowl of oil is enough), then cool it, take one or two raw egg yolks and always stir them in one direction. Never change the direction. Add the oil little by little, not too fast. After each addition, stir the oil completely before adding the next spoonful. If it is too fast, it will be difficult to mix it evenly until the oil is completely used up. Finally, add white vinegar, salt and monosodium glutamate to it. As for the amount, it depends on personal preference. I once added some mustard, and it tasted good. I suggest you go to the supermarket to buy salad dressing. It's too much trouble to make it yourself. In the past, when salad dressing was not sold in the market, my family made it by itself, and it took about an hour to stir it every time.