How to Make It
To prepare the duck, remove any giblets, reserving neck for potatoes. Rinse duck under cold water, pat dry with paper towels, and place on a rimmed baking sheet. Prick duck with a fork liberally over every surface. Let stand, uncovered, in refrigerator for 8 to 12 hours.
Combine 1 tablespoon salt, 2 teaspoons black pepper, and pink peppercorns in a small bowl. Season inside and outside of duck liberally with the spice mixture. Insert shallot and thyme sprigs inside cavity. Truss the duck; rub outside of duck with Maggi Seasoning sauce to coat.
Place the potatoes in a large cast-iron skillet. Drizzle with 1 tablespoon olive oil and lightly season with 3/4 teaspoon salt and 1/4teaspoon black pepper. Place sage sprigs and duck neck in skillet with the potatoes.
Prepare a charcoal grill for two-zone cooking and build a medium-high fire, or heat a gas grill to high. When the coals are glowing red and covered with a layer of fine gray ash, add 2 cups mesquite wood chips. Carefully wipe the preheated grates clean, then carefully spray with cooking spray.
When the fire begins to produce a steady stream of smoke and temperature registers 300-325°F, use tongs to remove the cooking grate, and place the skillet of potatoes on the side with no coals. Replace the cooking grate, and place the duck, breast side up, directly on the grate over the skillet of potatoes. Close grill, vent the grill for smoking, and smoke until an instant-read thermometer inserted in the thickest part of the breastreads 140°F, about 1 hour, turning duck and stirring potatoes once, adding coals or wood chips as needed to maintain a steady temperature between 300°F and 325°F. Transfer duck to a cutting board, and let rest for at least 20 minutes. Remove potatoes from the grill when tender; remove duck neck and sage, and discard or save for stock. Let potatoes cool slightly; cut in half, and toss with juices in skillet to coat.
Whisk together vinegar, mustard, remaining 3 tablespoons oil, remaining 1/4 teaspoon salt, and remaining 1/4 teaspoon black pepper in a large serving bowl. Add the frisée and warm potatoes; toss to combine. To serve, carve the duck into 6 to 8 pieces; tuck into salad.