can i drive with a boot on my left foot

Short answer: in an automatic, usually yes; in a manual, probably not unless you fancy stalling your way through every set of lights. The law in Australia boils down to being in proper control of the vehicle; if your left foot is in a boot and you drive a manual, working the clutch safely is, shall we say, ambitious. In an auto, the left foot isn’t needed for pedals, but you still must be comfortable, pain-free, and able to react properly. Check with your doctor (and insurer) before driving, and avoid it if you’re on meds that impair alertness. If a roadside check shows you’re not in proper control, expect a fine and a lecture that lasts longer than your recovery. When in doubt, let someone else drive and enjoy being chauffeured for once.