Step 1Place garlic, ginger, tomato sauce, vinegar, pineapple juice (not pieces), sugar, soy sauce, stock and water in slow cooker and stir well. Add onion, capsicums and chicken. Set to low and cook for 7 hours.
Step 2Remove lid, stir well and add peas and pineapple pieces. Cook for 30 more minutes.
Step 3Meanwhile, cook rice following packet directions.
Step 4With 30 minutes remaining, combine cornflour with enough cold water to form a smooth paste and add to slow cooker. Continue to cook for 30 more minutes.
Step 5Stir in spinach then serve with rice.