That's not quite right. In Europe three phase wiring is delivered via a 5 core wire: 3 phases, neutral and earth (ground). You can take any phase wire, and the voltage between that and neutral will be 230V. For higher power devices, the voltage between any two phases will be 400V.
My induction hob can be connected to 1 phase or 3 phase power, there's a dip switch on the back to switch it over. I'd imagine inside it changes the voltage and frequency to something completely different depending on what power level you set the burner to, so the actual supply voltage isn't that important.
