Slice up the onion and remove the peel.

Place the onion on baking sheets or dehydrator trays.

Turn the oven or dehydrator to about 150-170ºF (or as low as the oven goes).   Dry for 5-6 hours or until completely firm with no mushiness/wetness at all.

Grind the dried onions in a small coffee or spice grinder. Store in a small glass jar.