150mlapple cider vinegaralternative: a mild white wine vinegar, for example white balsamic vinegar
150mlwater
50mlmaple syrup
1tspsalt
Instructions
Peel the onion and cut into very thin slices (rings) with the mandolin or knife).
Pour into a glass with a lid with a capacity of approx. 500 ml.
In a bowl or measuring cup, combine apple cider vinegar, water, maple syrup, and salt. Pour over the onions. The onions should be covered by the liquid. If not, just add equal amounts of vinegar and water.
Close the jar tightly and leave in the fridge overnight.
The onions will keep, tightly sealed, in the refrigerator for 2 to 3 weeks.