PREHEAT oven to 400° F. Line large baking pan with foil.
PLACE parsnips, carrots and fennel in prepared baking pan. Add oil and salt. Toss with hands to coat. Roast in oven for 20 minutes until parsnips and carrots are cooked but still slightly firm.
PREPARE pasta according to package directions, omitting oil. Meanwhile, heat half-and-half and tarragon in a small saucepan over low heat, pressing down on tarragon to release more flavor. Drain pasta and return to saucepan. Add warm cream mixture and roasted vegetables; toss gently to combine. Serve with pepper and cheese.