Dried Fruit Cookies with Walnuts

In a meat grinder (or a strong food processor) grind apricots, raisins and prunes together.
Wet (or oil) your hands to prevent sticking, and transfer ground fruit into a deep, large bowl. Add cocoa powder, starch, powdered sugar, juice and egg white. Mix well with your hands until ingredients are completely integrated.
Make small balls (½ size of a golf ball) out of the mixture. After forming each ball, flatten it a little bit between your palms, and press a walnut half into it. You should get between 32-35 with this amount of ingredients.
Transfer granulated sugar into a smaller bowl. Roll each cookie boat in granulated sugar and set on a flat pan or a baking sheet lined with parchment paper.
Leave in a dark, cool place to dry for a few hours. Later, when they toughen, transfer dried fruit cookies into a container or a cookie jar, and keep it in the fridge, or a cool, dark place for up to two weeks. If keeping them in the fridge, take them out a little bit before serving so they get to room temperature.