Part of our kitchen has a sloping ceiling; plasterboard nailed to the
sloping roof rafters.
This section is not insulated.
What is the best, and what is the easiest way to do it? Should I
take off the plaster, lower the ceiling by 3 inches, and pack between
the joists and the extra space with fibre - a relatively big job....
or could I successfully take an easier route; drill holes and inject
something - expanding foam maybe?

Thanks

Tony