PREPARE GRILL: Heat all burners on high for 15 minutes. Leave primary burner on high and turn other burners off. Scrape and oil cooking grate.

COAT PORK: Meanwhile pat pork dry with paper towels. Combine mustard seeds, coriander seeds, peppercorns, salt and cornmeal on rimmed baking sheet. Place cornstarch in large bowl. Beat egg whites in second large bowl until foamy. One at a time, coat tenderloin lightly with cornstarch, dip in egg whites, and transfer to rimmed baking sheet to coat with spice mixture.

GRILL PORK: Spray tenderloins lightly with cooking spray and grill, covered, over hot side of grill, turning occasionally, until browned all over, 6 to 8 minutes. Slide pork to cooler side of grill and continue to cook, covered, until meat registers 145ᵒ, 6 to 12 minutes longer. Transfer pork to carving board, tent with foil, and let rest 5 minutes. Slice and serve.