Heat the oil in a large, high-sided frying pan over high heat. Season the chicken with salt before searing in the pan for 2-3 minutes on each side, or until golden. Transfer the chicken to a plate.
Add the butter to the pan. When the butter is starting to foam, add the flour. Cook, stirring for 1 minute or until the mixture bubbles. Stir in the curry powder. Remove from heat and gradually whisk in 2 cups of water.
Return to medium heat and add the apple juice, ketchup, soy sauce, star anise and cinnamon. Cook, stirring, until the mixture thickens. Simmer for 5 minutes to allow the flavours to develop.
Add the chicken pieces back into the pan along with the frozen vegetables and garam masala. Cook, stirring, for 3 minutes or until the vegetables have warmed through.
Scatter spring onion on top, and serve with steamed rice.
