Preheat oven to 425°F. Combine mustard, steak seasoning and rosemary in small bowl. Rub evenly onto all surfaces of beef roast.
Line sheet pan with parchment paper. Add cabbage and cranberries to the sheet pan. Toss with oil, salt and pepper. Place roast on bed of cabbage and cranberries. Do not add water or cover. Insert ovenproof meat thermometer so tip is centered in thickest part of beef. Roast in 425°F oven for 1 hour, 10 minutes for medium rare, 1 hour, 20 minutes for medium doneness.
Remove roast when thermometer registers 135°F for medium rare; 150°F for medium. Transfer roast to carving board; tent loosely with aluminum foil. Let stand 15 minutes. (Temperature will continue to rise about 10°F to reach 145°F for medium rare; 160°F for medium.)
Carve roast across the grain into thin slices; season with salt and pepper, as desired. Serve with roasted cabbage and cranberries.
Garnish roast and cabbage mixture with balsamic syrup or cranberry sauce.
Nutrition information per serving: 296 Calories; 108 kcal Calories from fat; 12 g Total Fat; 4 g Saturated Fat; 6 g Monounsaturated Fat; 88 mg Cholesterol; 478 mg Sodium; 14 g Total Carbohydrate; 5 g Dietary Fiber; 32 g Protein; 2.7 mg Iron; 8.7 mg NE Niacin; 0.7 mg Vitamin B6; 1.7 mcg Vitamin B12; 5.6 mg Zinc; 35.1 mcg Selenium; 115.6 mg Choline;