In a large, self-sealing plastic bag, shake the salt, sumac and juniper together. Add the duck breasts and shake to coat. SEal and refrigerate at least 1 hour or overnight. Remove from the refrigerator and bring to room temperature.
Preheat your oven to 400°F. In a large ovenproof sauté pan, add enough oil to generously cover the pan and set over medium-high until shimmering. Working in batches so you don’t overcrowd the pan, sear the duck breasts, skin side down, for about 5 minutes. Turn and sear the other side for 5 minutes. Place the pan in the oven and roast for 5-7 minutes for medium rare. Transfer breasts to a plate and tent to keep warm.
Pour all but about 1 teaspoon of fat from the pan and reserve for another use. Return the pan to medium heat, add the cider and scrape up the browned bits from the bottom of the pan. Stir in the sage and simmer the cider to reduce by half. Add the vinegar and cook to reduce for several more minutes. Season with maple syrup. Cut the duck breasts into 1-inch-thick diagonal slices and served drizzled with Wojape.