Smoked Duck with Potatoes and Frisée

Name: Smoked Duck with Potatoes and Frisée
Ingredients: 1 (4 1/2- to 5-pound) duck (thawed, if frozen); 4 teaspoons kosher salt, divided; 2 1/2 teaspoons coarsely ground black pepper, divided; 2 teaspoons ground pink peppercorns; 2 ounces shallot, quartered; 3-4 thyme or oregano sprigs; 1 1/2 tablespoons Maggi Seasoning sauce; 1 1/2 pounds small Yukon Gold potatoes; 1/4 cup extra-virgin olive oil, divided; 2 sage sprigs; Cooking spray; 1 1/2 tablespoons red wine vinegar; 1/2 teaspoon Dijon mustard; 4 cups chopped frisée (from 1 medium head)