Caramelized Onion Relish - cooking recipe

Ingredients

2 tablespoons salted butter
2 large sweet onions, halved and thinly sliced
1/4 cup dark brown sugar
6 garlic cloves, thinly sliced
1 cup red wine
2 tablespoons cognac
3 tablespoons balsamic vinegar
generous pinch kosher salt
1 pinch black pepper

Preparation

Melt butter in a large pot and add the onions and sugar.
Cook, uncovered,over medium high heat for 30-45 minutes, stirring occasionally - the onions will be beginning to caramelize.
Stir in the garlic, wine, cognac and vinegar.
Bring to a boil, then reduce heat and cook for 15 minutes, stirring often.
Add salt and pepper, then spoon into jars and process in a waterbath for 30 minutes.