Beans on toast?

The basics are pretty self-explanatory to Britons, but:

• Which type of beans is it?
• Does it have to have a tomato sauce?
• Did you know you can put melted cheese on it?
• Did you know that beans were good for your heart, but the more you eat, the more you fart?
• How many servings are made per year?
• If you put all those servings end-to-end, how far would it go?
• Okay, but what’s that in double-decker buses or olympic swimming pools?
• Does anyone outside the UK eat it, or similar meals?
• Who invented it? Where?
• Did you know that in London, they don’t have bread, so they have beans on eels instead? (citation needed)

Plenty of info/questions/facts to be found.