Yep, kitchen is a Part P Special Location so a new lighting circuit is notifiable. If you aren't on a scheme, you need to notify your Building Control before you get started. As for your lighting circuit, you need to start from the beginning. What's the load? What correction factors for installation method? Once you've done your calcs, you'll know what size conductor and what rating you need for your switch/switches. Will your junctions be accessible for initial verification and IR in the future? There may be some parts that need to be MF connections. I'm surprised a trainee would say "I've got a kitchen, 12 downlighters and a switch and a load of 1mm, how do I wire it all together?"
