Heat oven to 350°F Combine 2 tablespoons thyme and garlic-pepper seasoning; press evenly onto all surfaces of beef roast.
Place roast, fat side up, on rack in shallow roasting pan. Insert ovenproof meat thermometer so tip is centered in thickest part of beef, not resting in fat. Do not add water or cover. Roast in 350°F oven 1-3/4 to 2 hours for medium rare; 2 to 2-1/2 hours for medium doneness.
Remove roast when meat thermometer registers 135°F for medium rare; 150°F for medium. Transfer roast to carving board; tent loosely with aluminum foil. Let stand 15 to 20 minutes. (Temperature will continue to rise about 10°F to reach 145°F for medium rare; 160°F for medium.).
Meanwhile skim fat from drippings. Combine drippings, shallot and 2 teaspoons thyme in medium saucepan. Cook and stir over medium heat 2 to 3 minutes or until shallots are crisp-tender. Stir in wine and mustard; bring to a boil. Reduce heat; simmer 8 to 10 minutes or until sauce is reduced to 3/4 cup. Stir in butter. Season with salt and pepper as desired.
Carve roast into slices. Serve with sauce.