Inspired by Alinea's Burnt Onion Stick, this is a garnish I do for long cooked meats (think 72hr short rib) and pressure cooked onion soup. You can also burn the entire stick to ash for ash coating.
Cut onion and/or leek into strips ~12mm x 80mm and separate into individual layers. Place 100% onion/leek into a bag and add 100% of a 1:1 simple syrup. Ensure the strips are not over lapping and vacuum on high. If you do not have a vacuum chamber place the strips into a simmering 1:1 simple syrup for one minute.
Remove from the bag/syrup, pat dry and place flat on a silpat. Place in a dehydrator/low oven until dry and stiff (check after an hour, you want the sticks dry to the touch). Once dry use a blowtorch to burn one end of the stick. The onion/leek will easily catch fire so take care. Store in an airtight container. Best used the day they are made.
The stick is stiff and can be used to add height to a plate and/or cantilevered over the edge of a piece of protein. The bitter burnt part of the onion/leek is tempered by the sweet unburnt end.
