Hi again everyone.
Im happy my post has at least been taken seriously ;D
Just a few points to clarify matters having now read the various members posts
Firstly I add the old oil is to the base only.
I start a fresh curry in the pan using fresh oil, as some members have also observed being done in various commercial kitchens
In previous posts, other members have often observed chefs adding excess oil scavanged from finished dishes back into the base saucepan.
So, same result as making Base with old oil from the outset surely?
And thats a good reason why sometimes commercial kitchen curries can have an off day taste wise, as the base may be too new & hasnt yet had or had enough old/ scavenged oil added back in.
Finally, one member mentioned that even reheating oil once is dangerous, surely all chip shops would therefore being breaking health & safety laws as they change their oil usually only on a weekly basis.
Lastly using old chip oil as another member suggested definitely does NOT work and will produce a disgusting taste.