Heat a wok on medium and spray well with 1 kcal spray.
Add the garlic and the onion and sweat for two minutes.
Add the chicken and and brown slightly.
Add the ginger, peppers and carrots and stir fry for a further 5 minutes (until chicken is white throughout).
Meanwhile in a small bowl, combine the cornflour, soy sauce, pineapple juice, tomato puree and white wine vinegar.
Add the sauce to the stir fry and bring to the boil.
Stir in the pineapple chunks.
Season with salt & pepper to taste and serve immediately with rice, noodles or cauliflower rice.