3 lbs. beef short ribs (I used boneless, but bone-in would also work), 6-8 portions
2T olive oil
salt and pepper
1 medium onion, chopped
2 carrots, peeled and chopped
2 stalks celery, trimmed and chopped
2 cloves garlic, minced
1c beef broth
6T good balsamic vinegar
2T brown sugar
2 (14.5oz) cans diced tomatoes