Capital Sauce. I'd had this dish once years before at a city centre restaurant and wanted to confirm how nice it was. I'm glad to say it was even better than I expected & so I decided to find out more about it.
Apparently it's a plum sauce, which I found in the supermarket (Tung Chun brand), with vinegar, tomato puree & chilli (I used flakes), salt, herbs (I used parsley) & water. While it was simmering, I pan fried strips of steak, onions & bell peppers in a little oil & put on a pan of rice, then added to meat.
The result was very close to original but in some ways seemed even better. Not sure why! I have half the plum sauce left so I'll try another variation soon :-)