Bring a saucepan of water to the boil and cook the rice based on packet instructions.
Heat the sesame oil and sunflower oil in a work or frying pan and stir fry the onion and garlic for 3-4 minutes.
Add the carrot and broccoli and stir fry for another 2 minutes.
Add the beef strips and stir fry for 4-5 minutes.
Mix the cornflour with 1 tablespoon of cold water and stir in the beef stock.
Stir this into the pan, together with the sugar, soy sauce and toasted sesame seeds.
Bring to a simmer and cook for two minutes before serving with the rice.