Potato, Celeriac and Apple Mash

A nice recipe from Riverford Organics, this.  It doesn't look any different from ordinary mash, but the lovely smokiness from the celeriac and the sweet note from the apple complemented some roast pork loin and red cabbage perfectly.  Basically, you cook equal quantities of peeled and cubed celeriac and potato (I like King Edwards) and then mash them with a little butter and cream, and a peeled chopped apple cooked in a tiny bit of water until soft..  Season with salt and lots of black pepper.  I imagine this would be great with bangers and onion gravy with, perhaps, some pan-fried apple slices on the side.