Use up your root vegetables in this wonderful version of scalloped potatoes using turnips and rutabagas.
1½ cups Water
1½ cups Dijon mustard
2 tsp All-purpose flour
Salt and pepper
2/3 cup Dry white wine
½ cup Heavy cream
½ Onion, finely chopped
1½ tsp Fresh thyme
1 Garlic clove, minced
2 lb Yukon Gold potatoes, peeled and sliced into 1/8 inch slices
1 Celery root (1 lb) peeled, quartered, and sliced into 1/8 inch slices
1 lb Rutabaga, turnips or combination, peeled, quartered, and sliced into 1/8 inch slices
¾ cup Panko bread crumbs
1 ½ oz Parmesan cheese, grated
4 Tbsp Unsalted butter, melted and cooled
Heat oven to 350 degrees. Grease 13” x 9” baking dish
Whisk 1 Tbsp water with the mustard, flour and 1 ½ tsps of salt in a bowl until smooth. Add cream, wine, and remaining water and then whisk to combine.
Combine onion, thyme, garlic, ad ¼ tsp pepper in a second bowl.
Layer half of the potatoes in the greased baking dish. Sprinkle half of the onion mixture over potatoes. Arrange celery root and rutabaga slices then add remaining onion mixture. Layer remaining potatoes on to.
Slowly pour water mixture over vegetables. Press down vegetables to create an even dense layer. Cover with foil and bake for 50 minutes. Remove foil and bake 20-25 minutes more until potatoes are done.
While potatoes are baking, combine the bread crumbs, cheese and butter in a bowl and season with salt and pepper to taste. Remove gratin from oven and sprinkle mixture over top. Continue to bake until panko is golden brown about 15-20 minutes more. Remove and let stand 25 minutes before serving.