I have completely rewired my house (The house had been stripped to the
bare walls and joists). The only thing left to do is put in a new
Consumer Unit and wire all the circuits to it. All the cables come
into a cupboard under the staircase through the ceiling.

I am installing a surface mount MK sentry Consumer Unit. My question
is how should I route all these cables into the Consumer Unit? Do they
all have to be put into trunking and then fed into the top of the CU?
Or is it better to chase channels and bury the cables and feed them
into the CU from the back? There's a hell of a lot of cables there.

Any advice appreciated.