1. Peel potatoes, wash and cut into strips, and put them in a bowl;

2. Add salt, egg yolk and custard powder and mix well for later use;

3. Heat the oil in the pot to 50% heat and add French fries;

4. Fry slowly on low heat until golden brown, take it out and put it on a plate;

5. Leave a little oil in the pot, add tomato sauce and sugar, and stir fry a few times;

6. thicken with water starch, serve on a plate and serve with French fries.