1 tbsp olive oil
1 large yellow onion, finely diced
6 cloves garlic, minced
1 28-oz can diced tomatoes (or 2 lbs fresh, diced + 1/4 cup water)
1 tbsp tomato paste
2 tbsp red wine vinegar (or balsamic vinegar)
1 1/2 tbsp sugar (or 1 tbsp if using balsamic vinegar)
1 tsp dried oregano (or 2 tsp fresh, chopped)
2 tsp dried rosemary, crushed (or 1 1/2 tbsp fresh, finely chopped)
salt and pepper to taste