File this under simple & satisfying. It's not as strongly flavored as most dishes usually described as sweet & sour, but it's that kind of flavor profile. The purple cabbage is a great color.
1.5 cups quick barley
4 leeks, cleaned & sliced
1/4 of a red cabbage, sliced
Sautee the leeks and cabbage in butter and sugar in the bottom of a soup pot. Add 3 cups of water, a dollop of bullion, a heavy splash of rice vinegar, and cook till the barley has soaked it all up.