Chopped up over a kg of onions and fried them, also added grated parsnip and carrots, then salt, pepper and a few bottles of malt vinegar. Little bit of honey too. Simmer away for a few hours, add more vinegar if it's getting a little dry. Then store in jars.

This was 2 days ago and my kitchen still smells divine. I don't really know how to accurately describe it. Caramelised onions but there is more to it from the vinegar. Doesn't smell like vinegar though, more like it's enhanced the onions.

Cheap to make as supermarkets here are competing over selling the cheapest veg. 5kg of parsnips, carrots, cabbage and swede for under £0.50, onion was a bit more, but not much. Was going to add all of it but my arm was getting tired from grating and peeling so much. I don't own a food processor so it's all by hand. Filled 2.5L worth of jars from the first batch.