Wipe roast with damp paper towels. Combine flour, mustard, salt and pepper. Rub all over beef. Place roast, fat side up, with ribs as rack, in roasting pan (insert thermometer). Roast, uncovered, 3 to 3 1/4 hours or until thermometer registers 140 degrees (rare) or 4 1/4 hours, 160 degrees (medium).

Let roast stand 15-20 minutes for easier carving. Serve au jus or with brown gravy.

Makes 7-8 servings.