Mike comes in to devise a tasty indulgence (5,3)
I believe the answer is:
cream tea
'tasty indulgence' is the definition.
The definition suggests a singular noun which matches the answer.
'mike comes in to devise a' is the wordplay.
'mike' becomes 'M' (phonetic alphabet: alpha, bravo, charlie etc.).
'comes in to' indicates putting letters inside.
'devise' becomes 'create' (I've seen this before).
'm' inserted into 'create' is 'creamte'.
'creamte'+'a'='CREAM TEA'
Can you help me to learn more?
(Other definitions for cream tea that I've seen before include "Macerate (anag) - light meal" , "Meal with scones and jam" , "Supposedly civilised afternoon meal" , "snack" , "calorie-packed meal" .)