The traditional way to eat an artichoke is to cook them (whole in the water, or steam them) and serve whole with a bowl of butter. You pluck the leaves one by one and dip the fat end in the butter, then scrape it away with your teeth. Thats really hard to describe. Um, when you pull the leaf out there will be a fleshy bit at the bottom - thats the part you eat. Then discard the rest of the leaf. Keep going until you reach the centre. Thats the moist, tender, expensive part. Then you will encounter the "choke" which is a hard hairy bit, don't eat that. Throw it away.
They look massive but not that much food on them sadly. 50c each is really good though, they're normally wickedly expensive!
They's fancy food