Peel potatoes. Dice into ½-inch pieces. Rinse. Add to pot with salt and enough water to cover. After water comes to a boil, lower heat and let potatoes cook in salted water for about 7 minutes to soften slightly, but do not overcook.
While potatoes are cooking, make the duck fat, either of two ways: 1) Melt the ½ cup of purchased duck fat; or 2) cook (and render the duck fat from) about 6 pieces of duck bacon. If using duck bacon, after completion of cooking, remove duck bacon and let drain on paper towels. Keep warm.
When the duck rendering is ready, turn off heat and prep the potatoes.
Drain the potatoes really well, as dry as possible.
Turn on heat again for the duck fat and then slowly add potatoes. Cook on a low heat. If the mixture is dry, add a few pieces of unsalted butter. Sprinkle with Kosher salt and Black Pepper. Turn potatoes as they brown on each side. Add Herbs De Provence on each side as potatoes continue to cook. After potatoes are golden brown, remove from pan and let drain on paper towel. Transfer to serving plate. Add spring of rosemary and top with duck bacon (if using).
*Herbs De Provence is an assortment of dried herbs that are used in Southern France. Typically, I wouldn’t use dried herbs, but in this instance, there is an exception to my rule. I make my own HDP, which consists of dried basil, fennel seed, lavender, marjoram, rosemary, sage and thyme.