In the US the receptacles are single phase 110v and almost always only one circuit has been run from the panel so you cannot convert over to 220. Another line would have to be run from the panel. The only 220 circuit in the kitchen tends to be for the range. Either way it means $$ to get the setup for the counter top oven.( unless you know how to do it your self, however I do not recommend this for the everyday DIY guy ) 35 years electrical experience.
My house has central heat and air..that said we still have the electric coiled wall heaters built into the walls that run off 220 volts to the fuse box.There are two of them with their own 220 circuits.
We do not use the wall heaters anymore,but they do work if we switch them ON.Btw,this is in the USA if it matters.
That said,could an electrician use this already wired 220 set up down at the box and use the current wires or run new wires into the kitchen somewhere if we bought a stove like posted above?We don't need the wall heaters and never use them anyway.
Just wondering what you thought.