Use a clean 1 quart glass jar for making syrup and storing.
Layer small handful of chopped onions and about ⅛ cup sugar. Keep layering until jar is full.
Shake the jar a bit so the onion is all coated and leave it on the kitchen counter.
In about 2 hours the onions will have reduced by about half.
In 12 hours it's done! You can begin using the syrup at this point.
Remove the spent onion bits after 2 or 3 days and put the jar of syrup away for when needed.
Serve by the teaspoonful when needed for coughs and colds.