By request, for mom:
1 stick unsalted butter
2# onion halved and cut crosswise into 1/2″ slices
1/2 t fresh ground pepper
1/2 c sugar
2T dry sherry
1/4 c red wine vinegar
1 c red wine
1/4 c honey
Melt butter til it foams. Add onions, stir until coated. Sprinkle with s/p, reduce to low heat. Cook, stirring occasionally, until golden, about 20 minutes.
Add remaining ingredients and cook uncovered until quite thick, and dark, a couple of hours. Stir as needed to keep from burning. Season to taste. Keeps in fridge for a long long time.
Good with any meat, with cheese, and on sandwiches. It’s quite rich, so you don’t need a lot of it.