CHICKEN GYOZA WITH GREEN RICE

1tbsp reduced salt soy sauce, plus an extra 1⁄2 tsp to serve | 1 lime, juice | 1tsp maple syrup | 120g frozen edamame beans | 240g pack frozen itsu Chicken Gyoza | 1tbsp Vegetable oil | 2 salad onions, finely sliced (greens and whites separated) | 1tsp finely grated ginger | ½ pointed spring cabbage (about 250g), shredded | 250g pack microwaveable wholegrain rice | 1tsp Japanese rice vinegar | Few drops chiu chow chilli oil (optional)