A bacon & egg cob. I've had a bacon & egg cob at work every Friday for 15 years. It started very innocently, when a colleague suggested breakfast cobs one Friday. The next Friday I reciprocated. By the 3rd Friday Cob Club was official and there were rules (you don't talk about cob club, if it's your first time, you have to buy the cobs, etc).
When I left that job and came to my current employment in 2007 I instigated it here. Cob club has had as many as 8 members, and sometimes it's just me, but it always happens.
It doesn't have to be B&E; sausages, tomatoes, mushrooms, hash browns are all allowed. If you can get it inna cob, it's in.
Actually, it's such a broad church that porridge is allowed - and you don't have to have it inna cob.
I suspect that breakfast cobs, or some sort of extra breakfast indulgence on a Friday, might be a thing anyway. But I quite like the idea of it being a club. It helps to generate some cohesion in our team. We sometimes talk work, but we don't have to. However we always co-ordinate on Thursday evening and make sure that no-one who wants a cob is missed out.