Trim fat from tenderloin. Sprinkle tenderloin all over with salt and pepper. Heat oil in a roasting pan over medium-high heat; add tenderloin. Cook 6 to 8 minutes, turning often to brown all sides. Remove tenderloin to a cutting board. Rub tenderloin with garlic and 2 Tbsp. rosemary, pressing to adhere. Return to pan. Bake, uncovered, at 400° for 40 minutes or until a meat thermometer inserted into thickest part of tenderloin registers 140° (rare) to 160° (medium). Remove tenderloin to a serving platter; let stand 10 minutes before slicing. Arrange Balsamic Peppers around tenderloin, and garnish, if desired.