Sprinkle roast with seasonings. Place roast, fat side up, on rack in a shallow roasting pan. Insert meat thermometer into thickest part of the meat. Bake at 325° for 1 1/2 to 2 hours or until meat thermometer registers 160° (30 to 35 minutes per pound).

Drain cherries; reserve liquid, and add water to make 3/4 cup, if necessary. Tie cloves and cinnamon in a cheesecloth bag. Combine 1/2 cup cherry liquid, sugar, vinegar, and spice bag in a saucepan. Bring to a boil; reduce heat, and simmer, uncovered, 10 minutes. Remove spice bag.

Combine cornstarch and remaining 1/4 cup cherry liquid; stir into hot liquid. Cook over medium heat, stirring constantly, 1 minute or until thickened and bubbly. Stir in cherries, lemon juice, and butter.

Place roast on a platter. Serve with sauce.