State of roast regularly served up in rented house (7)
I believe the answer is:
lesotho
'state' is the definition.
(Lesotho is an example)
'roast regularly served up in rented house' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'served up' indicates anagramming the letters.
'in' is an insertion indicator.
'rented' becomes 'let' (I've seen this before).
'house' becomes 'ho' (abbreviation for house**).
The alternating letters of 'roast' are 'os'.
'os' with letters rearranged gives 'so'.
'so' going into 'let' is 'lesot'.
'lesot'+'ho'='LESOTHO'
'of' acts as a link.
(Other definitions for lesotho that I've seen before include "African country, formerly Basutoland" , "Southern African country, capital Maseru" , "Country, an enclave of South Africa, capital Maseru" , "He loots (anag) -- southern African kingdom" , "Independent kingdom, an enclave of South Africa" .)