You could try making your own sweet and sour sauce, it's quite easy! Finely slice some onion, garlic and carrots.Fry in olive oil until soft. Put in a tin of chopped tomatoes. Heat to simmering point. Add a good splash of balsamic vinegar and a tablespoon of brown sugar. Add chinese '5 spice' to taste and simmer until slighty thickened. OK, you will probably tell me you can't get hold of chinese 5 spice. Maybe there is a chinese supermarket in Tortosa? Anyway, it is possible and cheaper to make your own if you use it regularly, so maybe worth a try!