Using a mandoline, slice Idaho® potatoes and sweet potatoes into 1/8 inch slices. Pat the Idaho® potato slices dry with a paper towel. For a decorative pattern, use leaf shaped cookie cutters to cut enough slices of sweet potato to line the bottom of a 10-inch skillet.
Warm clarified butter so it becomes a liquid. Stir in orange zest and cumin.
Heat an ovenproof 10-inch skillet over medium heat. Brush the bottom of the pan generously with enough of the clarified butter mixture to evenly coat the entire pan.
Working as quickly as possible, line the pan with the decorative leaf shaped sweet potatoes so the bottom of the pan is completely covered. Sprinkle with a pinch of berbere. Working in a circular pattern beginning at the center, add a layer of Idaho® potatoes, slightly overlapping to cover the decorative layer entirely. Drizzle this layer with more of the clarified butter mixture, sprinkle generously with salt, and another pinch of berbere. Repeat with sweet potatoes.
Continuing alternating layers of Idaho® potatoes, clarified butter and spices, and sweet potatoes until the pan is full. If you have excess clarified butter leftover at the end, do not drizzle it over the top.
Press the layers down into the pan using a spatula or the bottom of another skillet. Skillet should be sizzling.
Tent loosely with foil, transfer to the oven and bake for 30 minutes. Remove foil, and continue to cook until potatoes are easily pierced with a fork, about 15 more minutes.
Remove pan from oven and run a spatula around the edges to loosen the mixture. Allow to cool then turn out onto a plate. Slice and serve.