Reportedly, this is a viking recipe.
Heat the apple pieces and leaves in water until boiling. Sweeten with honey and serve hot.
I'm going to try this (sans leaves) tomorrow as I am baking bread. I will report back if it is as tasty as it sounds in theory.
** Edited to Add **
I didn't have leaves but I did chop up and apple and throw it into a pot of water to boil. I think the next time I attempt this, I am going to use more apples because it was a really weakly flavored result with what I did. If I had cooking apples, I suspect it would have worked out better as well. So, my next attempt will be a ratio of 1:1 apples to water, where as I had used 1:2.