Make the rub: Coarsely crush the coriander seeds in a mortar with a pestle, in a spice mill or coffee grinder, or by wrapping them in a dish towel and crushing them with the edge of a heavy skillet. Combine the crushed seeds and the remaining rub ingredients in a mixing bowl and mix well with your fingers.
Set up the grill for indirect grilling (for charcoal or for gas) and preheat to medium-low. If using a charcoal grill, place a large drip pan in the center. If using a gas grill, place all the wood chips in the smoker box or in a smoker pouch and preheat on high until you see smoke, then reduce the heat to medium-low.
When ready to cook, brush and oil the grill grate. If using charcoal, toss 1 cup of wood chips on the coals. Brush the excess rub off the turkey with a paper towel. Place the breast in the center of the hot grate over the drip pan, away from the heat; cover the grill. Grill the breast until tender, 1½ to 2 hours (the cooking time will depend on the size of the breast and the heat of the grill). To test for doneness, use an instant-read meat thermometer. The internal temperature should be at least 170°F. If using a charcoal grill, you’ll need to add 12 fresh coals and ½ cup wood chips per side after 1 hour.
Transfer the turkey pastrami to a platter and let cool to room temperature, then refrigerate until cold. To serve, cut the pastrami into thin slices across the grain. Serve on rye bread slathered with mustard.