Frozen oven chips homemade

I was reading a mag in the hairdressers, which is the only reason I go there LOL, and it had how to do your own frozen oven chips.  But the old memory not being like it never was there is a part I am not sure of............I'll run it through you.  Cut fat chips, par boil for 2-3 mins, dry, freeze on a tray, now this is the bit do you then toss in the one tablspoon of oil and put back in freezer OR do you do the toss in oil bit when you are about to cook them.  I am almost sure it was the first one oil and back in freezer.

Thanks

Very Simples!! Just thought though surely what I described is just roast tats on a smaller scale.....eh! LOL

Didn't think of that until daughter mentioned it .........I'm gonna swat that girl.

Yeah think I am getting to that stage where the daughter becomes the mother.