For the rice: In a saucepan, bring water to a bowl. Once water is boiling, add rice and a pinch of salt, and lower heat to a simmer. Cover. Continue to cook the rice for 20 mins, or until the rice is tender. Uncover the rice and fluff with a fork.
Add thawed mixed vegetables to rice and stir. Add chicken, rice and vegetable in an oven safe casserole dish and stir gently to combine.