Place the beef strips into a ziploc bag with the cornflour, toss and set aside.
In a jug, add the ginger, soy sauce, water and brown sugar.
Prepare and chop all the vegetables. Drizzle a little olive oil into a frying pan or wok and cook the onion, chives, leek, eggplant and garlic till the onion starts to brown.
Add the red capsicum, followed by the spinach cooking for another 5 to 7 minutes. Remove cooked vegetables and place in a bowl.
Add a little more olive oil and fry the steak browning on each side, but leaving the middle a little pink (you may need to cook in two batches). Once cooked place in another bowl and set aside.
Pour sauce mix into the frying pan or wok and bring to boil, add the sesame seeds, followed by the cooked beef and mix.
Pour in the vegetables and mix. The cornflour used on the steak should thicken the sauce, however, if you find it isn't thickening enough add 1 tablespoon of cornsflour to 1 tablespoon of cold water in a mug - stir then add it to the pan.