Last week we got a whole bag of turnips in our share. Turnips!
Pommes Anna is a French dish of thinly sliced potatoes, baked in a cocotte à pommes Anna (or, you know, a skillet) with lots of butter to form a cake. (The Epicurious recipe has exactly two ingredients: potatoes and butter).
Martha extends the dish to include rutabaga in her "roots Anna," and her somewhat more complicated recipe was the one I happened on first. I substituted turnips for the rutabaga, used our whole bag of turnips instead of a mere two pounds, and felt extremely dubious that a turnip dish was going to be an appealing centerpiece at dinner.
An hour later ... I was impressed. I wasn't daring enough to try to turn the cake out of the pan, but the slices were tender and buttery, and purply and deeply caramelized on the bottom, and probably the best turnips I've ever cooked (no, that's not a high bar). Not a leftover turnip to be seen this morning.
I'm pretty sure you could use any combination of roots and tubers you have on hand (potatoes, sweet potatoes, turnips, rutabaga, celeriac, parsnips). Slice them as thinly as possible, and arrange the slices in concentric circles in the bottom of a buttered ovenproof skillet. Add salt, pepper, and more butter between each layer. Cover the top layer with foil, weigh it down (Martha suggests putting a cast iron pan on top), and bake for an hour at 450 degrees. If you're brave, try to turn it out of the skillet.