Recipe: Caramelized Red Onion Relish

You need to have the acid to make it safe to can, to prevent botulism as onions are low acid vegetables. You cannot omit either the wine nor the vinegar. I see other recipes online with a bunch of oil or butter, which is not safe. You would not have to use red onions, any kind will work.

CARAMELIZED RED ONION RELISH

2 large red onions, peeled
1/4 cup firmly packed brown sugar
1 cup dry red wine
3 tbsp balsamic vinegar
1/8 tsp each salt and freshly ground pepper

Slice onions into very thin slices. Combine onions and sugar in a heavy non-stick skillet. Cook, uncovered, over medium-high heat for about 25 minutes or until onions turn golden and start to caramelize, stirring frequently.

Stir in wine and vinegar. Bring to a boil over high heat, reduce heat to low and cook for about 15 minutes or until most of the liquid has evaporated, stirring frequently. Season to taste with salt and pepper.

Remove jars from canner and ladle relish into jars to within 1/2 inch of the rim. Process for 10 minutes for half-pint jars.