Tomato sauce is an unrivalled and essential ingredient in making great sweet and sour sauce-google it, its so easy. I also use it at every opportunity as an ingredient in making marinades for pork ribs/belly along with honey, mustard, sugar, salt, vinegar, pepper etc.
Where are those recipes from though? What we call "tomato sauce" in North Americas is NOT catsup. "Tomato sauce" here comes canned and just contains concentrated tomato juice and a few herbs/spices (no vinegar) It's sole use is as an ingredient in cooking more complex dishes. You have another name for it over there, unfortunately I can't recall it at the moment.
Tomato Puree.
Best one is Hungarian Double Concentrated, Golden Pheasant Brand.
I think the Chinese are turning in their mass graves that Ketchup is used in making Sweet & Sour sauce...
ketchup is originally an European concoction. Made with mushrooms and such. Mama Heintz, being dirt poor and without mushrooms, did the best she could. and look what has become of her cooking, one of the Worlds mightiest companies!
Join Heintz, Nestle, Monsanto and Mackedonaldo and we do not need any Polititians.
Tomato purée or passata.
The first one handily comes in tubes, excellent for camping but because it's pre-cooked it can be an odd flavour in further cooked sauces. Passata on t'other hand is just cleaned and squeezed tomatoes without skins or seeds.
M