Can I install a plug on a hard-wired cooktop?
Canadian practice is very similar to US practice. 

Stoves and ovens typically live on a 40A or 50A circuit.  

It is common to provide receptacles for them, but 40A receptacles are not made, so the (US) National Electrical Code has a special exception allowing 50A receptacles on 40A circuits. 

Sometimes the oven and stove are separate, but on the same 40A or 50A circuit, in which the NEC allows two receptacles to be provisioned.