In a large microwaveable
dish, mix the ketchup, vinegar, sugar and
garlic thoroughly with the chicken, onion
and peppers. Microwave, uncovered, on
High for 8-10 minutes until the chicken is
starting to cook and the sauce is sizzling.
Stir in the pineapple pieces
and sugar snap peas and return to the
microwave for another 3-5 minutes until
the chicken is completely cooked. Leave
to stand for a few minutes, then stir in the
cashews, if using, and serve.