UK cooking appliances are a little different to US ones in that often people have 2 seperate parts:
The oven part, single ovens are usually rated at 3kW and can be plugged in. Double ovens 4-5kW would be hard-wired on their own circuit but should have an isolator above the counter.
The top bit where the pans go are often 7-8kW and are always hardwired, also with an isolator
The more traditional cooker, all in one is always wired on its own circuit, usually in 6mm on a 30a breaker/fuse Mine is like this and is 13.5kW
The cable used to connect the appliance to the outlet plate is the standard Twin and Earth cable
Traditionally, a special Cooker Connection Unit was installed and you would often see the cable going to this in trunking. Slightly more recently, another part, the outlet plate is installed behind the cooker
