Heat oven to 425°F. Combine seasoning ingredients; press 1/2 onto beef Tri-Tip Roast. Combine remaining seasoning with oil and vegetables in large bowl; toss.
Place roast on rack in shallow roasting pan. Place vegetables around roast. Do not add water or cover. Roast in 425°F oven 30 to 40 minutes for medium rare; 40 to 50 minutes for medium doneness.
Remove roast when instant-read thermometer registers 135°F for medium rare; 150°F for medium. Transfer to board; tent with foil. Let stand 20-25 minutes. (Temperature will continue to rise about 10°F to reach 145°F for medium rare; 160°F for medium.)
Meanwhile increase oven temperature to 475°F. Remove peppers. Continue roasting potatoes and onions 10 minutes or until tender and lightly browned. Carve roast across the grain. Serve with vegetables.
Nutrition information per serving: 330 Calories; 90 kcal Calories from fat; 10 g Total Fat; 3 g Saturated Fat; 5 g Monounsaturated Fat; 66 mg Cholesterol; 269 mg Sodium; 29 g Total Carbohydrate; 4 g Dietary Fiber; 26 g Protein; 2.8 mg Iron; 8.6 mg Niacin; 0.9 mg Vitamin B6; 1.3 mcg Vitamin B12; 4.8 mg Zinc; 27.4 mcg Selenium; 114.6 mg Choline;