I used 3 table spoons of flour and 1 table spoon of potato starch. Then I added water (around 7 table spoons of water) until the mixture is fluid. It needs to be pretty fluid, do not make it too thick. Don't forget to add salt, otherwise the coat doesn't have flavour.
This is the result: If you fry it a second time, it will be crispier.
I think the hash browns were not salted enough, so next time I'm going to add more salt. I also think the potatoes were cooked for too long, so I will cook them less the next time.
To see how you make the hash brown, go here.