Thaw short ribs in refrigerator overnight, then remove and pat dry on both sides with a paper towel.
Season with kosher salt, pepper, cumin, and garlic powder on all sides. Allow to sit on counter for 20 mins.
Place short ribs in large re-sealable zipper bag and pour marinade over short ribs. Massage the short ribs inside the bag with marinade, then all to marinate in refrigerator overnight, at least 4 hours.
After marinating overnight, remove short ribs from marinade and let them come to room temperature on a large plate, about 20 to 25 mins.
Preheat grill to 425F direct heat, clean and oil grates with grapeseed oil.
Grill short ribs over direct heat 4 to 5 mins on each side, until golden brown and cooked through, then glaze with pomegranate glaze. After two minutes, flip short ribs again, glaze the other side, and let cook an additional 2 minutes until well-lacquered on both sides.
Remove from grill and place on cutting board. Use kitchen shears or a sharp knife to cut short ribs between each bone. Serve hot over shaved Brussels sprout sauté, drizzle with pomegranate glaze, and finish with sesame seed garnish.