Begin with what I did there in restaurant? (8)
I believe the answer is:
initiate
'begin' is the definition.
(I've seen this before)
'what i did there in restaurant?' is the wordplay.
I cannot quite see how this works, but
'i' could be 'a' and 'a' is found in the answer.
'in' is within the answer.
This explanation may well be incorrect...
'with' acts as a link.
Can you help me to learn more?
(Other definitions for initiate that I've seen before include "Begin - teach" , "Bring up a topic or prepare the way for" , "Originate" , "Kick start" , "Admit with rites into a society" .)