Having taken apart my old crappy kitchen I have found that my oven
power cable has a plug on the end and is plugged into a normal plug
socket, I always thought that they had to go into a 30amp box, is that
correct?

Assuming thatI am correct and it does have to go into a 30amp box I
need to find somewhere to put it. The current 30 amp oven box has the
garage power supply attached to it (4 plug sockets, 2 security lights
and 2 halogen strip lights) bearing in mind I use power tools, garden
tools and the occasionally a MIG welder from the garage, is it ok to
take feed out of this 30 amp box so it supplys the garage and the oven?

Cheers for you help, I'll be back soon with more stupis kitchen related
questions.

Dave