Broccoli chicken cashew nut stir fry

Name: Broccoli, chicken & cashew nut stir fry
Ingredients: 1 tbsp soy sauce; 2 tsp seasoned rice vinegar or white wine vinegar; 1juice of 1 small orange; 1 tsp dark muscovado sugar; 2 tsp cornflour; 2 tbsp stir-fry oil or vegetable oil; 385g unsalted cashew nuts; 1medium onion, thinly sliced; 1large skinless boneless chicken breast fillet, cut into chunks; 250g broccoli florets; 150g pack mangetout, sliced in half; 1 red pepper, seeded and thinly sliced