Ground rule ultimately matching stocks as stir-fry option (6,3)
I believe the answer is:
sesame oil
'stir-fry option' is the definition.
I can't tell whether this definition defines the answer.
'ground rule ultimately matching stocks' is the wordplay.
'ground' becomes 'soil' (synonyms).
'ultimately' suggests the final letters.
'matching' becomes 'same' (I've seen this in another clue).
'stocks' means one lot of letters goes inside another (stock' can mean 'fill').
The last letter of 'rule' is 'e'.
'e'+'same'='esame'
'soil' enclosing 'esame' is 'SESAME OIL'.
'as' is the link.
Can you help me to learn more?
(Another definition for sesame oil that I've seen is " Substance obtained from seeds".)