I like to use fingerling potatoes for this recipe, but other any type is fine also. Just be sure to cut them into pieces sized for about two bites.

I like to use fingerling potatoes for this recipe, but other any type is fine also. Just be sure to cut them into pieces sized for about two bites.
Preheat oven to 375 degrees. Heat the oil and butter over medium-low heat in a large ovenproof skillet or baking pan. Add onion slices, and cook until very soft, about 15 minutes. Stir in the potatoes and shallots and half the rosemary leaves; season with a good amount of salt and pepper. Raise heat to medium-high, and cook until potatoes begin to brown, about 10 minutes more. Remove from heat, and add remaining rosemary leaves and the stock.
Cover skillet or baking pan with a lid or a piece of foil, and transfer it to the oven; cook until potatoes are fork-tender, about 15 minutes (timing will vary with size of potatoes). Uncover, and cook until liquid is reduced, about 30 additional minutes. Sprinkle with minced rosemary. Serve warm.
serves 4
Source:Adapted from Martha Stewart Living