- 2 5-lb. whole Pekin ducks
- 2 large onions, quartered
- 1 bunch large rosemary, divided
- Kosher salt and freshly ground black pepper
- 3 pounds small Yukon Gold potatoes, peeled
- 2 pints fresh black Mission fig or Turkish figs, halved
Preheat oven to 425°. Set ducks, breast side down, on a work surface and score fatty areas along backs and thighs with a paring knife, being careful not to cut into flesh. Turn over and score fat, concentrating mainly on breasts but extending to tops of legs. Poke a few holes around extra-fatty areas of cavity.
Stuff ducks with onions and all but 4 sprigs rosemary; season generously with salt and pepper (much of the seasoning will melt away as the fat renders).
Place ducks, breast side down, in a large roasting pan; pour in ½ cup water. Roast, rotating pan occasionally, until duck fat starts to render, water is evaporated, and skin is golden brown, about 40 minutes. Remove pan from oven and transfer ducks to a platter or baking dish. Carefully pour rendered fat into a heatproof measuring cup.
Toss potatoes and ¼ cup duck fat in roasting pan (save remaining fat for another use); season with salt and pepper. Scoot potatoes to perimeter and return ducks to pan, breast side up. Roast until potatoes and dark meat are tender and an instant-read thermometer inserted into breasts registers 155°, 50–60 minutes. Transfer ducks to a cutting board; let rest at least 10 minutes before carving.
Meanwhile, add figs and remaining 4 rosemary sprigs to pan; toss well. Roast until figs are soft and juicy, 5–8 minutes. Serve duck with figs and potatoes.