It's usual to dish out gruel with a warm heart (7)
I believe the answer is:
regular
'it's usual' is the definition.
(similar in meaning)
'dish out gruel with a warm heart' is the wordplay.
'dish out' indicates anagramming the letters (I've seen 'dished out' mean this).
'with' says to put letters next to each other.
'heart' indicates the central letters.
The centre of 'warm' is 'ar'.
'gruel' with letters rearranged gives 'regul'.
'regul'+'ar'='REGULAR'
'to' is the link.
(Other definitions for regular that I've seen before include "Normal, steady" , "Soldier - uniform" , "fighter" , "Perishes" , "Usual; done frequently" .)