Ingredients 1 bone-in pork rib roast (8 ribs; 6 to 7 pounds, depending on size), frenched, fat cap trimmed to 1/4 inch thick Kosher salt (we use Diamond Crystal) and freshly ground pepper 1/3 cup Dijon mustard, plus more for serving 3 tablespoons reduced-sodium soy sauce 3 tablespoons finely chopped fresh rosemary leaves, plus 3 sprigs 2 tablespoons coriander seeds, crushed 2 tablespoons fennel seeds, crushed 1 1/2 pounds small potatoes (golf-ball-size), such as red bliss or fingerling 1 pound unpeeled cipollini onions, or 2 medium Vidalia onions, peeled and cut into 1-inch-thick wedges 3 small fennel bulbs (about 1 pound), trimmed and cut into 1-inch-thick wedges 3 tablespoons extra-virgin olive oil, divided 4 sweet-tart baking apples, such as Braeburn or Honeycrisp (1 3/4 pounds) Preparation Score rib-roast fat cap with the tip of a paring knife in opposite directions, to create a 1/2-inch crosshatch....