Thanks to all (i.e. the usual helpful few!)

To try and answer some of your questions:

The units will all be built in and spread around an 'L' shaped area of
worksurface interspersed with drawer units.

I think that the drawer units really make access to sockets behind
unreasonably fiddly and I'm not prepared to have FCUs or appliance
sockets above the worksurface.

There is only one 'cupboard' providing the possible option of locating 3
FCUs and then running radials to sockets close to each appliance. This
under the sink which is approx 2/3 from the top of the upright in the
L. This is why I said something about lengthy cables in the original post.

If it was my choice I would not provide any isolation, but just put
single, possibly switched, sockets close to each unit and use the MCB in
the CU as an isolator.

It is only the installers who said that each appliance must be supplied
by an FCU/socket pair and cannot simply be plugged into the kitchen ring.

I understand what you say (Christian) about using 6mm cable - I had
feared as much!

The CU is some distance from the kitchen and, needless to say, hidden in
an under-stairs cupboard. In any case is it acceptible to have the MCB
as the only way of isolating the kitchen appliances, especially the
hood? If it is it might be easier to show SWMBO how to test the RCD
which is separate from the CU and thus more accessible!

A big red emergency off button has a certain appeal - is that feasible
(only half joking)? Some sort of remote test switch for the RCD would
have the desired result. Have I heard/read about kitchen over-heat
sensors that can trip the power supply to the kitchen? Presumably they
trip a suitably rated contactor? The ones supplying the last mainframe
room that I worked in used to stick on!!

Cheers guys

Richard