Microwave sweet & sour chicken

Name: Microwave sweet & sour chicken
Prep time: 10 min
Cook time: 15 min
Total time: 25 min
Cuisine: Chinese
Ingredients: 9 tbsp tomato ketchup; 3 tbsp malt vinegar; 4 tbsp dark muscovado sugar; 2 garlic cloves crushed; 4 skinless and boneless chicken breast cut into chunks; 1 small onion roughly chopped; 2 red peppers seeded and cut into chunks; 227g can pineapple pieces in juice, drained; 100g sugar snap peas roughly sliced; handful salted, roasted cashew nuts optional