The flavour of sweet and sour originates from Wuxi in the Zhejiang province in China - it is most known for its sweet and sour soy sticky ribs. They are traditionally braised in stock for an hour and then the sauce is added and thickened. However, in true modern style, I love marinating pork fillet slices in homemade sweet and sour sauce, then wok-fried to perfection (until sticky) and stuffed in griddled seeded buns with caramelized red onions and plenty of salad leaves which in my opinion is the ultimate party food - for children, football matches or BBQ's!
Heat a wok over high heat and add the 2 tablespoons groundnut oil. Add the sliced pork and stir-fry until browned for about 3 to 4 minutes. Lastly, pour in the marinade and reduce the heat. Cook so the sauce achieves a sticky consistency, a further 2 to 3 minutes.
To make the onions: Heat a small wok or pan, add the groundnut oil and stir-fry the red onions until translucent and softened, about 4 to 5 minutes. Then, add the black rice vinegar, and brown sugar, and caramelize for another minute.
For service: Heat a griddle pan, add some groundnut oil, and place the sliced seeded buns, cut side down, and grill until browned slightly. Stuff the buns with some of the salad leaves, some of the sticky pork slices, caramelized onions, and sliced red tomatoes. Serve immediately.