Slice onions into thin slices about 1/4 inch (6 mm). Place on dehydrator sheet and dry at 130°F (55°C) for 2-3 hours.
Dry until onions slices are very dry and brittle, and not leathery. Check often to remove dried slices. When done; pour into a coffee grinder, blender or food processor and blend.
Leave powdered onions in blender to settle for 10 minutes or more. Store in a glass jar.
