Mix the Sauce ingredients in a bowl.

Heat the oil in a wok or large heavy based skillet over high heat until it is smoking.

Add the onion and garlic and cook for 1 minute or until the onion becomes translucent. Keep it moving so the garlic doesn't burn.

Add the beef and stir fry for 1 minute until just cooked to your liking, then remove into bowl.

Turn the heat down to medium high, pour in Sauce - it will start simmering very quickly! Let it cook for 1 minute or so until it becomes syrupy - the bubbles will be larger and caramel colour.

Add the beef and onion back into the wok, along with any juices pooled on the plate. Toss in the sauce until just warmed through - 1 minute at most. Don't overcook the beef - that would be tragic!

Serve immediately with rice - or for a low carb, low cal option, try Cauliflower Rice!