To make the sauce: In a small heavy-bottom saucepan, whisk the sauce ingredients with 1/2 cup water. Bring to boil over medium heat, then reduce the heat and simmer for 10 minutes, stirring occasionally.
To make the rub: In a spice grinder, pulse the peppercorns and the mustard seed until coarsely ground. Place in a small bowl and add the remaining rub ingredients, mixing well.
Allow the chops to stand at room temperature for 20 to 30 minutes before grilling. Lightly brush or spray the chops on both sides with oil and season with the rub, pressing the spices into the meat. Grill over Direct Medium heat until barely pink in the center of the meat, 8-10 minutes, turning once. Remove from the grill and let rest for 3-5 minutes. Serve warm with the sauce on the side.