With a hand blender, beat egg whites and sugar, until they are well combine. Add water, melted butter, and vanilla essence, and combine it well. Add flour, and combine it well to avoid lumps. You will end up with a whiteish mix.
Preheat the oven at 350F. On a baking tray, place a piece of parchment paper or silicone. Place a tablespoon of the mix, and flatten it in a round motion. I make three at the time. When they are golden, about 7 minutes in the oven, take them out, place a fortune paper, fold it in half, and curve it in half with the help of the border of a mug. Place them in muffin tray to maintain the shape. BE CAREFUL.....you have to do it while they are hot because once they get cool is impossible to shape them.