Preheat oven to 325 F. Line two baking sheets with parchment paper. Cream the shortening with the white sugar and ground almonds. Form into lumps the size of golf balls. Place on baking sheet in well spaced rows. Press lumps lightly, just to flatten, with the bottom of a drinking glass.
Paint tops with egg yolk and water mixture.
Bake until cookies look set - 15 to 20 minutes.