Preheat the oven to 350 degrees. Grease a baking pan and set aside.
Combine the water, soy sauce, sugar, ginger, cumin and garlic in a pot over medium heat. Add the cornstarch and mix until boiling. Keep boiling until the sauce thickens and remove from the fire.
Place the chicken breast cubes in the prepared pan. Pour half of the sauce over the chicken and take to the oven. Bake for 30 minutes. Take out from the oven
Add the carrots, peas, rice and the remaining of the sauce and with the help of a wooden spoon mix until everything is coated. Take to the oven and cook for an additional 10 minutes.