Shirley_online said:
... At the moment there is no electric cooker connection/switch at all, just ordinary electric sockets...
Then, basically, you need to have a Cooker Circuit installed. An electric cooker takes a lot of power, so you will need this new circuit, with heavy cable and a large switch. It will have to be connected to your consumer unit (fusebox) and if the existing one is old and/or small it may have insufficient capacity so a new one will be needed.
Installing a new circuit, and electrical work in kitchens, are both subject to regulations, so you need a qualified electrician who is a member of a Self Certification scheme and will carry out the necessary tests and give you a certificate when completed. An unqualified handyman or a DIYer is not permitted to do this work.
This may sound more than you were expecting, but it is a very common job for a domestic electrician.
Best thing is to ask around friends and neighbours for local recommended electricians; then phone some and ask if they are members of a self certification scheme. ask which one, and how long they have been full members (preferable not to have someone who's still learning). You can check this.
You want two or three quotes. Decide which electrician you feel most comfortable with, and try to speak to one or more of his recent customers to see how pleased they were.
If you want to avoid all this, consider either a gas cooker, or a Dual Fuel cooker, with a gas hob and a single electric fan oven. Most of these can (check!) be plugged in to an ordinary socket as they take less than 13Amps/3000 watts, and don't need a special cooker circuit. They also give very good cooking results.