1. Prepare a proper amount of tomatoes, clean them with clear water for later use, add water to the pot to boil, then steam the prepared tomatoes for about 6 minutes, turn off the fire when the time comes, and take them out to cool.

2. After the tomatoes are slightly cooled, remove the skins and pedicels of the tomatoes, cut the pulp, and then put it into a juicer to squeeze into tomato juice.

3. Add a spoonful of cooking oil to the pot and prepare a small amount of onion and garlic to be chopped. When the oil in the pan is hot, add chopped onion and garlic and stir fry. After frying, take out the onion and garlic, and put the prepared red juice into the pot.

4. After the tomato juice is put into the pot, boil it with high fire. After boiling, add 200 grams of rock sugar and 4 grams of salt, and stir constantly while cooking, so that the rock sugar is completely dissolved in water. When the water in the pot becomes half of the original, turn to the minimum fire and continue cooking for about 5 minutes. When the tomato sauce in the pot becomes sticky, drop a few drops of white vinegar and continue to stir fry for 5 minutes, then turn off the heat.

5. Prepare several clean containers without water and oil. The tomato sauce can be eaten directly or poured into a container and sealed after it is slightly cooled.