Sweet and sour pork (koe loe yuk)

Ingredients

• 500 grams of pork (preferably pork tenderloin)
• 1 tablespoon rice vinegar
• 1 tablespoon salty soy sauce
• 100 grams of flour
• 1 tablespoon baking powder
• pinch of salt
• 1 egg
• 100 ml water
• 1 red pepper (bell pepper)
• 2 onions
• oil for frying
• white rice, to serve
• dash of sunflower oil
• 1 tablespoon fresh root ginger
• 2 garlic cloves
• 100 ml tomato ketchup
• 100 ml rice vinegar
• 6 tablespoons pineapple juice
• 1 tablespoon cornflour (cornstarch)