Roast Pork with Sweet-and-Sour Chile Cilantro Sauce

Preheat oven to 400 °F. Coarsely crush coriander seeds with a mortar and pestle or an electric coffee/spice grinder, then stir together with bread crumbs, oil, pepper, and salt in a small bowl. Turn pork so a long side is closest to you and season with salt and pepper. Pat one third of seasoned crumbs onto pork, leaving a 2-inch border along top edge. Starting with side nearest you, roll meat into a cylinder and tie securely with kitchen string. Coat pork with remaining crumbs. Roast pork on a rack in a roasting pan in middle of oven 15 minutes. Reduce temperature to 325 °F and roast until an instant-read thermometer diagonally inserted at least 2 inches into meat registers 155 °F, 1 to 1 1/4 hours more. Let pork stand, loosely covered, 10 minutes.