1. Separate 3 egg yolks from the eggs, beat them up
2. Boil the milk in a pot
3. Put in sugar to melt
4. Pour in evaporated milk and stir evenly, turn off the heat and set aside to warm up
5. Sift in low-gluten flour and stir until there are no particles
6. Pour the egg yolk liquid and stir well
7. Filter twice and it becomes tart water
8. Put purple potato filling on the bottom of the tart
9. Pour the eighth-full tart water
10. Preheat the oven at 190 degrees for about 18 minutes
Tips:Filter the tart water twice to make it more delicate
