You might say mixed pesto goes into marinade (2,2,5)
I believe the answer is:
so to speak
'you might say mixed' is the definition.
I can't tell whether this definition defines the answer.
'pesto goes into marinade' is the wordplay.
I cannot really understand how this works, but
an anagram of 'pesto' is 'tospe' which is present in the answer.
The remaining letters 'soak' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for so to speak that I've seen before include "In a way" , "as one might say" , "If one may use that expression" .)