A sexual/nutritional act ideal for parties or BBQs. A woman lies on her back with her breasts exposed (the bread), and the chef (sex is unimportant, but for the sake of flavour ideally someone with a garlic-rich diet) curls out a brown trout between her tits (the meat) before a male participant then Harry Munks over it (the cheese). Hungry party goers can then take the cheese burger in both hands and chomp away.
The act gained its "Hackney" monkier from the London borough where it was first performed following the complete consumption of all regular BBQ food stuffs.
Bob - Hey, we're all out of hotdogs but I'm still starving.
Mike - Don't worry, I'm baking one off so I'll grab the misses and get her to rustle us up a couple of Hackney Cheese Burgers.
Directly influenced by the Bukakke craze that swept Japanese secondary schools in the late 90s, a Hackney Trilby is the act of several men blasting off in to a trilby (or any brimmed hat) and placing it on to the head of a subject (often male).
So called because the practise originated in Hackney amongst the homosexual gangster hairdressing scene (hence why the only people who wear trilbys in Hackney are gay hairdressers).
Dave - Did you borrow my hat last night?
Mike - Sorry mate, we were down the Angel gagging for a Hackney Trilby and it was the only one around... do you want it back?