Preheat oven to 400 degrees F. Rinse the chicken with cool water, inside and out, and pat dry with paper towels. Season the cavity with salt and pepper, then stuff with lemon, garlic, rosemary, thyme, and sage. In a food processor combine the parsley and butter and process until well combined. Season the butter with salt and pepper.

Place the chicken, breast side up, in a roasting pan. Tie the legs of the chicken together with kitchen twine. Rub the herb butter over chicken. Put the mushrooms in the bottom of the pan; roast chicken and mushrooms for 1 hour 45 minutes, until the drumsticks move easily in their sockets and the juices run clear (180 degrees F in the thickest part of the thigh). Baste the chicken with the drippings and rotate the pan every 30 minutes to ensure a crisp, golden skin. Remove the chicken to a platter, tent with foil, and let stand for 10 minutes before carving.