This dish, with its simple ingredients and stunning presentation, might serve you well this busy holiday season. It's appealing to the eye and most diets, uses the best of what we have around in December, and travels well. Perhaps you have a potluck on the calendar? Maybe this wants to go with you. Prep the potatoes through step 8, about 2-3 hours ahead of time and hold the dish in the refrigerator until you're ready to bake it up. Choose a beautiful dish to bake this up in. A 9-inch round baking dish or any shaped casserole that holds around 2 quarts will work nicely. If you have little people underfoot in the kitchen, put them to work. They may be interested in stacking the potatoes for you, matching up the rounds by size. It's always nice to have an extra hand in the kitchen, especially on a cozy, December day.

2 pounds yellow potatoes
2 pounds sweet potatoes
3 tbsp. salted butter, plus more for the pan
3 tbsp. olive oil
2-3 sprigs rosemary
2-3 cloves garlic
coarse salt and pepper

  1. Peel the garlic. In a small saucepan over your lowest stovetop setting, melt the butter. Add in the oil, garlic, and rosemary sprigs. Leave this mixture on low to infuse the flavors. If it starts to sizzle or brown, turn off the heat, cover, and swirl occasionally as you prep the other ingredients.
  2. Butter or oil the entire inside of your baking dish.
  3. Preheat the oven to 375F.
  4. Peel the sweet potatoes. Scrub the yellow potatoes. (There is no need to peel these.)
  5. With a food processor or mandolin, slice all of the potatoes thinly. As you work, be sure to keep the sweet potatoes and yellow potatoes separate, placing them in two different piles.
  6. Strain the flavored oil/butter mixture. Pour a little into the bottom of your prepared dish, spread it, and set the rest aside.
  7. Working from the outside of the dish, begin to create a spiral of potatoes. Stack 3-4 of the sweet potato thins together, turn them on the side, and place in dish vertically. Repeat with the yellow potato. As you work, alternate the two colors to achieve a simple striped pattern. When you reach the center, do your best to create some symmetry.
  8. Pour the oil/butter mixture over the top and sprinkle liberally with salt and pepper.
  9. Bake at 375F for 1 hour and 50 minutes. If it's browning too quickly, cover it loosely with foil, removing it for at least the last 15 minutes of baking time.

Notes:

  • Yes, go ahead and double the olive oil or do half olive, half coconut oil, if you need to make this dairy free. You can, of course, also make it with just one type of potato.
  • Serves fine warm or room temperature, if needed.
  • Serve with a dollop of creme fraiche or sour cream on the side, if you feel like adding another dimension.