In a liquid measuring cup whisk in order, starting with the honey, molasses, 1 teaspoon salt, sugar, pomegranate juice, and wine. Cook's Note: Starting with the sticky ingredients then adding the liquid makes it easier to blend.
Pour half of the mixture into a large resealable plastic bag. Add to the bag the peppercorns, vegetable oil, and steak. Seal and massage the steak a bit before letting it rest at room temperature for 1 hour. If you need more time than that, refrigerate it, but make sure to bring it to room temperature before you grill it.
Pour the rest of the marinade, onions, and garlic into a small saucepot over medium-high heat. Bring to a boil then cover and lower to a simmer until the liquid reduces and thickens, about 15 to 20 minutes. Set aside.
Heat the grill or grill pan to medium-high heat.
Remove the steak from the plastic bag and gently pat dry. Discard the marinade from the plastic bag. Season the steak on both sides with a sprinkle of salt. Place on the grill, it's totally okay if a few peppercorns from the marinade hang on for dear life and go for a ride on the grill with the steak.
Cook until the steak easily releases from the grill, about 5 minutes. Flip and cook the second side for 5 minutes more for medium rare, which is best for this cut. Remove from the grill to a plate, cover with aluminum foil and let the steak rest 10 minutes, allowing the juices to redistribute before you slice it. Make notice of the direction the muscles in the steak are traveling and make sure to cut across or perpendicular to that direction to achieve the most tender results. Place the slices of steak in a serving dish and pour the glaze and onions over the top.