Potato and Celery Root au Gratin

I’m a little embarrassed that I didn’t know what celery root (or celeriac) was before making this. It’s like I’ve been cooking all these years and just discovered the tomato or something. It’s hard to miss it on the shelf with its wrinkly skin and snarl of dirty roots so where have I been? When I decided to cook some I suspected I might have to visit several stores but found a pile at my first stop so apparently it’s common. Or I just got lucky. Either way, it’s turned out to be a happy discovery and makes me wonder what else I’m missing.

I used un-peeled red potatoes thinking they would add some color to the very brown and white gratin, which they did. They also held up very well, not falling apart like softer, more starchy potatoes might. My wife, Terri thought more starchy potatoes might be better since they would soak up more of the sauce and would contrast more with the texture of the celery root. She is probably right but it was gratifying fare with the red potatoes, as I’m sure it would be with almost any variety.

I kept this really simple with the exception of two slightly fancy, but easy to find cheeses—creamy and mild Fontina and Gruyere which is more savory and browns very well. I was skipping the bread crumbs so this was important. You could substitute half and half for the heavy cream (but why?). The celery root was mild but permeated the whole dish and though it does taste a lot like its cousin celery, it has a sophisticated, earthy flavor and adds texture that celery couldn’t.

Ingredients:

8-10 red potatoes (palm-sized rather than “new”)
1 celery root (softball-sized)
1 pint heavy cream
1 to 1-1/2 cups shredded Fontina cheese
3/4 cup shredded Gruyere cheese
salt
black pepper

Wash and cut the potatoes into 1/4 inch slices. Peel the celery root, quarter it and cut into 1/4 inch slices. Boil both for 15-20 minutes. You want the potatoes soft enough that a knife will go into them easily but still firm enough that you wouldn’t call them done. Drain and place a layer of the sliced potatoes and celery root in the bottom of a dutch oven or baking dish. Sprinkle with the shredded cheese using mostly Fontina on all but the top layer. Pepper each layer liberally and salt lightly if you like. The cheeses add enough salt that I find I don’t need it. Sprinkle the top layer with a little Fontina and cover it with Gruyere. Pour the cream over the entire dish, sprinkle with black pepper and bake at 375 degrees uncovered for 30-45 minutes or until the top is brown.