This recipe produces the kind of sweet and sour chicken that you would typically get from a Western Chinese takeaway. I very much doubt you could get anything remotely like it in China! But unlike the takeaway version, you'll be eating this when freshly made, so the batter will be crisp, not soggy, and the chicken tender and juicy rather than dry and stringy. And I don't know what takeaways put in the sauce to make it glow in the dark, but this sauce doesn't!
Make the Batter
Mix together the dry batter ingredients in a bowl. Stir in the water - your batter should be like very thick paint. If it's too thick, add a bit more water. Put the batter in the fridge to rest for half an hour.
Make the Sauce
If you're using bell peppers, chop them into pieces about 1 cm (half an inch) square and sauté them in oil on medium heat for a few minutes, just to soften them. Add the passata or ketchup, the vinegar, sugar, soy sauce, salt and pineapple chunks if using. Let them cook together for a few minutes, then taste. Add more of the flavourings if required to get a nice balance between sweet and sour. Let the sauce simmer and reduce until needed.
Prep the Chicken
If your chicken has any skin or bits of fat on it, get rid of them. Cut the chicken into cubes, about 2.5cm (an inch).
Cook the Chicken Balls
Turn your oven on low - you'll be frying the balls in batches, so they need to be kept warm. If you don't have a deep fat fryer you can use a large saucepann not more than half-full of oil. Heat it to 190°C (374°F). Dip each cube of chicken in the batter (I usually impale a cube on a skewer to make this easier) to get it well coated. If you're using a deep fat fryer, lower the cube into the fat and let the batter sizzle for a few seconds beforeremoving it from the skewer - this stops the chicken ball from sinking to the bottom and getting stuck on the mesh of the basket.
The balls need to cook for about 5-6 minutes until golden. When done, remove them and drain them and place on a baking sheet in the oven to keep warm while you cook the next batch(es).
Serve the Sweet and Sour Chicken Balls
You can either pour the sauce over the chicken balls, or place it in a separate bowl to use as a dipping sauce. Serve with egg-fried rice.