Celeriac has a nice earthiness to it, which is beautifully hearty when combined with potatoes and cheese. Adapted from From Asparagus to Zucchini, Third Edition.
1 celeriac bulb, peeled and sliced into 1/8-inch rounds
1-2 potatoes, peeled and sliced into 1/8-inch rounds
2 Tbs butter
1 Tbs flour
1 cup chicken or vegetable stock
1 cup grated Swiss or cheddar cheese
Salt and pepper, to taste
Preheat oven to 375F. In a wide sauce pan, simmer the slices of celeriac and potato for abour 15 minutes, until a fork can be inserted easily. Drain. Dry the pan and then use it to melt the butter and then whisk in the flour, stirring constantly. Once the the flour incorporates and starts to brown, add the stock and cook, stirring frequently, until it thickens. Add salt and pepper to taste. In a shallow oiled dish, alternate layers of drained root vegetables and the white sauce. Distribute the cheese evenly over the top and then bake for about 15 minutes or until golden brown.