Wash potatoes. In a medium saucepan, cook the potatoes and carrots, covered, in a small amount of boiling salted water for 12 to 15 minutes or until tender. Drain and let stand until cool enough to handle. Meanwhile, remove the rosemary leaves from the bottom two-thirds of each sprig, leaving the top leaves intact. Soak rosemary sprigs in a bowl of warm water for 10 minutes; drain.