Caramelized Red Onion Relish (Canning)

A great use for balsamic's sweet and tart flavor. An inexpensive balsamic is just fine for this recipe. The wine is the ingredient that acidifies the conserve and sets the tone, so it is necessary. Use an inexpensive but drinkable wine for this, the variety you prefer doesn't matter, as long as it's dry (so-called "cooking wine" is not an option, EVER, for ANYTHING). Serve alongside meats or sparingly as a pizza topping with a tangy cheese and some bits of prosciutto for a salty element. From "The Complete Book of Small-Batch Preservation".

• Ready In: 1 hr 20 mins
• Yields: 2 cups

Ingredients

• 2  large red onions, peeled and very thinly sliced (use a mandoline or food processor with slicing blade)
• 1⁄2 cup  firmly packed brown sugar
• 1  cup dry red wine
• 3  tablespoons  balsamic vinegar
•  salt and pepper (to taste)

Directions

1. Combine onions and sugar in a heavy non-stick skillet. Cook, uncovered, over medium-high heat for about 25 minutes or until onions are golden and starting to caramelize, stirring frequently.
2. Stir in wine and balsamic vinegar. Bring to a boil on high, then reduce heat to low and cook about 15 minutes, or until most of the liquid has evaporated, stirring frequently.
3. Season to taste and cool briefly.
4. Ladle relish into hot half-pint jars, leaving 1/2-inch headspace. Process in a boiling water bath for 10 minutes.