Marinate the meat with the cornflour, salt and the first teaspoon of oil and set aside for one hour. Combine all the ingredients for the sauce base in a separate bowl and set aside.
Add 1 tablespoon of oil to coat the wok and heat until just smoking. Spread the beef around the wok and sear for 1 minute until 80% done, remove from the wok and set aside.
Heat another tablespoon of oil in the wok over medium heat. Add the ginger slices, and let them caramelise for around 10 seconds. Turn the heat up to high and add the minced garlic, shallot/red onion, and the white portions of the spring onion. Toss and cook for 10 seconds.
Add the tomato wedges to the wok. Spread them around the wok in an even layer and let them sear for around 15 seconds. Then add the Shaoxing wine, and stir-fry the mixture for another 10 seconds until the alcohol has burned off. Push everything to one side of the wok.
On the cleared space of the wok, add the sauce base. Stir until bubbling to combine the flavours together.
Add the beef and any juices in the bowl back into the wok. Stir–fry everything on high heat until mixed well and sizzling (only takes about 20 seconds). Make sure you don’t overcook the tomatoes or they will completely disintegrate into the sauce!
Add the remainder of the spring onion and add the cornflour/water mix a little at a time until the sauce is thickened to your liking – you won’t need much as the sauce thickens as soon as it starts to heat. Let the sauce cook for 15 seconds after adding the last bit of the cornflour/water to make sure the cornflour is cooked.
Plate and serve immediately with a big bowl of white rice cooked in your rice cooker!