Mr Fawlty and I regularly chat in church (8)
I believe the answer is:
basilica
'church' is the definition.
(basilica is a kind of church)
'mr fawlty and i regularly chat' is the wordplay.
'mr fawlty' becomes 'basil' (I've seen this before).
'and' means one lot of letters go next to another.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternating letters of 'chat' are 'ca'.
'basil'+'i'+'ca'='BASILICA'
'in' acts as a link.
(Other definitions for basilica that I've seen before include "A large Christian church with two rows of columns (8)" , "Roman hall; church" , "Large place of worship" , "Roman Catholic cathedral with special privileges" , "Romanesque church" .)