Best quote in the film by far ^^^^ but your missing part of it.
"Try fat burger from now on, you can get ya self a double cheese with fries for £2.95 f@ggot"
hat quote comes before it all so in all it reads:
It goes as:
Vince: Why don't you try Fat Burger from now on? You can get yourself a cheese and fries for 2.95, faggot!
Brian: I like the tuna here.
Vince: Bullsh!t a$$hole, no one likes the tuna here!
Brian: Yeah well I do.