Place cornflour and water in bowl then mix. Add remaining Sauce ingredients.

Slice the beef into 1/4" / 0.5cm thick slices. Place the beef and 2 tbsp of the Sauce into a bowl and set aside.

Heat oil in a skillet over high heat. Add beef and spread out, leave for 1 minute until browned.

Stir beef for 10 seconds, then add garlic and ginger. Stir for another 30 seconds or until beef is no longer pink.

Pour Sauce and water into the skillet and quickly mix.

When the sauce starts bubbling, add broccoli. Stir to coat the broccoli in Sauce, then let it simmer for 1 minute or until Sauce is thickened.

Remove from heat immediately and serve over rice. Sprinkle with sesame seeds if desired.