Meanwhile, I boiled (in two separate pots) some potatoes and some celery root. I added a lump of cream cheese (also leftover) to the celery root and whizzed it with the stick blender. Add the cooked potatoes to that, mashed, tasted, add added butter and milk.
I put the meat mixure into a round baking dish and topped it will dollops of the potatoes, and chucked it into the oven to brown the potatotes a bit. And that was it. New dinner from leftovers. Why cow-herder's pie? Because there was no lamb to make it shepherd's pie.