Preheat oven to 450°. If applicable, remove neck and giblets from chicken, and reserve for another use. Rinse chicken with cold water, and drain cavity well. Pat dry with paper towels. Sprinkle 1/2 tsp. salt inside cavity. Place lemon half inside cavity.
Stir together pepper, rosemary, and remaining 1 tsp. salt. Brush outside of chicken with oil. Rub 2 1/2 tsp. pepper mixture into skin. Sprinkle remaining pepper mixture over both sides of breast. Place chicken, breast side up, on a lightly greased wire rack in a lightly greased shallow roasting pan. Add 3/4 cup water to pan.
Bake at 450° for 20 minutes. Reduce heat to 375°, and bake 30 minutes. Baste chicken with pan juices; drizzle with melted butter. Bake 15 to 25 minutes or until a meat thermometer inserted in thigh registers 165°, shielding with aluminum foil to prevent excessive browning, if necessary. Remove chicken from oven, and baste with pan juices. Let stand 10 minutes before slicing.
We tested with McCormick Gourmet Collection Crushed Rosemary.