Crispy Potato And Celery Root Cake

In a food processor or with a hand grater, shred the potatoes. Rinse the potatoes in cold water until the water runs clear. Shred the celery root, but do not rinse.

Drain the potatoes and wrap them in a clean kitchen towel. Squeeze out the excess water, or spin-dry in a salad spinner. It is very important that the potatoes be dry or the cake will be soggy. Mix the celery root with the potatoes, and season with the salt and pepper.

Heat a heavy-bottomed or non-stick medium skillet with sloping sides. Add 1 tablespoon each of the oil and butter and heat. Add the potato mixture to the pan. Using a spatula, press the mixture into a neat cake about 1 1/2 inches thick. Lightly brown the cake over medium-high heat for 4 or 5 minutes. Shake the pan to loosen the cake, reduce the heat to low, and continue to cook the cake, loosely covered, for 10 to 12 minutes.

To flip the cake, brush a flat lid, smaller than the cake, with oil, invert the cake onto the lid, and hold it aside for a moment. Raise the heat to medium-high and add the remaining butter and oil to the pan. Carefully slide the cake back into the pan, and cook, uncovered, until the bottom is golden brown, about 5 more minutes. Invert the cake onto the lid again and re-crisp the first side again for about 1 minute. Slide the cake from the pan onto a cutting board, cut into wedges, and serve.