In a food processor, grind pecan and walnuts. Pour into a bowl.
Place blueberries in food processor and add ground almonds and a little water.
Mix together blueberries and ground nuts.
Spread mixture onto dehydrator tray and spread it up to 1 inch (2.5 cm) thick. Dehydrate for 10 hours at 140°F (60°C), then flip bars over and dehydrate another 10 hours. When ready, cut into 18-20 bars.