What is this small white flower, sprouting out of a single large leaf?

Question

I recently found this flower on a north facing, shady bank in woodland (UK) with sandy soil. I've never seen anything like it before, a small, white flower sprouting out of a single, large leaf. What is it?

Answer 1

That is Claytonia perfoliata, known as Miner's Lettuce in the US. It's often used as a salad green in winter lettuce mixes. It's extraordinarily cold hardy. Not much flavor though (at least in my opinion).