Use potatoes similar in diameter so they stack nicely.

1 teaspoon garlic powder

1 teaspoon onion powder

1 teaspoon paprika

1 teaspoon freshly ground black pepper

1/2 teaspoon fine sea salt

1/2 teaspoon cayenne pepper to taste

2 large Yukon gold potatoes, unpeeled, sliced into 1/2-inch slices, ends discarded

2 large red potatoes, unpeeled, sliced into 1/2-inch slices, ends discarded

2 sweet potatoes, peeled, sliced into 1/2-inch slices, ends discarded

1/2 cup extra-virgin olive oil

Fresh rosemary sprigs

Fine sea salt