Preheat a gas or charcoal grill to medium. Brush the meat with olive oil and season with salt. Grill until well seared on ones side, 4 minutes, turn over, and baste with the Molasses Glaze. Continue grilling for 3 minutes, turn over, baste and grill for 2 to 3 minutes more (a total of 10 minutes), for medium rare. Let rest for 10 minutes; then slice into 8 steaks.
Heat the oil in a small saucepan over medium-high until almost smoking, and cook the onion until soft, 4 to 5 minutes. Add the garlic and ginger root and cook an additional 2 minutes. Add the rum and reduce until completely dry. Add the molasses, orange juice, and pepper, season with salt, and cook until reduced to 1 cup, 15 to 20 minutes. Let cool at room temperature. May be refrigerated, covered, for 1 day; use at room temperature.