Preheat oven to 400. For beef, sear beef in 2 Tbsp. oil in sauté pan over medium high heat til brown on all sides, 10 minutes; remove pan from heat.
For vegetables, toss potatoes carrots and shallots with 1 Tbsp. oil and season with salt and pepper. Press rosemary needles into cut sides of each potato and place in pan, cut side down. add carrots, shallots, and remaining rosemary needles to pan; transfer to oven
Roast beef and vegetables til an instant read thermometer inserted into thickest part of meat registers 125 to 130 for medium rare, 20 to 25 minutes; let rest 10 minutes. Slice beef and serve with vegetable s and sauce.