Preheat the oven to 450 degrees F. Pick the leaves off the rosemary sprig and toss them with the carrots, parsnips, 2 teaspoons Worcestershire sauce, 1 1/2 tablespoons olive oil, 1/2 teaspoon salt, and pepper to taste in a shallow baking dish. Roast, stirring once, until the vegetables are tender and golden brown, about 25 minutes.
Meanwhile, mix the garlic, chopped rosemary, the remaining 1 teaspoon Worcestershire sauce, 1/2 tablespoon olive oil, 3/4 teaspoon salt and 1/4 teaspoon pepper in a small bowl. Rub all over the steaks.
When the vegetables are halfway done (after about 12 minutes), heat a large skillet over medium-high heat and add the remaining 1/2 tablespoon olive oil. Working in batches if necessary, sear the steaks, 2 to 5 minutes per side for medium rare.
Transfer to a cutting board and let stand 5 minutes before slicing.
Serve with the roasted vegetables and drizzle with the pan juices.
Per serving: Calories 507; Fat 32 g (Saturated 11 g); Cholesterol 90 mg; Sodium 818 mg; Carbohydrate 19 g; Fiber 5 g; Protein 33 g