What was the child sent to buy?

One day Mrs Busy was throwing a dinner party for her friends with tastes as refined as hers. Amid preparations she noticed that she was missing a few important things, but didn't have the time to go buy them herself. So she sent her little daughter Susy to get those from the store.

Susy wrote herself a shopping list. She could read and write, but wasn't too good at spelling yet. Her mother hastily enumerated the missing items, spelling out some of the trickier words so Susy would get them right, while Susy wrote down everything without giving it a second thought.

The mind of a child wanders fast, and by the time Susy reached the store she had to consult the note to see what she was sent to buy. She found some of the items requested by her mother:

OLIVES BLACK

ICE CREAM VANILLA

GRAPES GREEN SEEDLESS

But the last item didn't make much sense:

TOO LONG FOP

Susy went to ask the store clerk whether they had any "too long fops". The clerk was as confused as Susy, until Susy showed him the note. The clerk looked at the note, took a few seconds to think, then burst out laughing and proceeded to get the missing item for Susy.

Can you figure out what the last item was?

I think the last item was

some Oolong tea. Mrs Busy thought "tea" didn't need spelling but "Oolong" did, so she said "tea O O L O N G"; little Susy heard "T O O L O N G" and put those letters together to make "TOO LONG".

However, I am still trying to figure out

what happened with FOP. It's most likely qualifying "tea, Oolong" just like "seedless" in "grapes green seedless" -- it might be a variety, or a quantity, or a mode of packaging. (Except that I can't think of any that would work.) Or perhaps the F was originally "if" and the meaning was something like "tea, Oolong if available", but I'm currently failing to see what might have sounded like "op" or "O P" with such a meaning.

• I was thinking something like: 2 long ephope but doesn't make sense xD – lois6b Nov 29 '16 at 12:05