Pork Rib Roast with Mustard Sauce

Rub

• 4 teaspoons kosher salt
• 1 tablespoon finely chopped fresh thyme leaves
• 1 teaspoon garlic powder
• 1 teaspoon freshly ground black pepper
• 1 teaspoon dried thyme

• 1 pork rib roast, about 6 pounds with 8 ribs, bones frenched

Sauce

• ¼ cup whole-grain mustard
• ¼ cup mayonnaise
• 2 tablespoons plain yogurt
• 2 tablespoons sour cream
• 1 tablespoon finely chopped fresh chives
• 1 teaspoon finely chopped fresh thyme leaves
• ⅛ teaspoon kosher salt
• ⅛ teaspoon freshly ground black pepper