New diet with a soft ingredient, not very hot (5)
I believe the answer is:
tepid
'not very hot' is the definition.
(I've seen this in another clue)
'new diet with a soft' is the wordplay.
'new' indicates anagramming the letters.
'with' means one lot of letters goes inside another.
'a soft' becomes 'p' (musical abbreviation for 'piano').
'diet' is an anagram of 'teid'.
'teid' enclosing 'p' is 'TEPID'.
'ingredient' acts as a link.
This may not be right. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for tepid that I've seen before include "What's a bit warm" , "Not very warm (water)" , "Slightly warm" , "Of liquid, luke-warm" , "without enthusiasm" .)