Heat 1 tablespoon of the oil in a heavy-based saucepan then add the rice, stirring with a spatula to ensure that the grains are coated with oil. Add the water, season, bring to simmering point, then cover and cook gently for around 15 minutes.
Chop the chicken fillets into small, even-sized pieces and season to taste. Place the sesame seeds on a plate and toss the chicken in them.
Heat the remaining oil in a nonstick saucepan and cook the chicken for 4–5 minutes, stirring regularly so that it browns on all sides. Stir in the spring onions.
Serve the rice with the sesame diced chicken.