Rinse chicken; pat dry with paper towels. Brush with oil. In a small bowl combine basil, oregano, parsley, and garlic salt; sprinkle on the outside of the bird, then rub in. Cover and chill for up to 24 hours.
For stuffing, in a large mixing bowl combine the spinach, red or green sweet pepper, prosciutto or ham, bread crumbs, green onion, pine nuts or almonds, melted margarine or butter, and pepper. Cover and chill for up to 24 hours, if desired.
Slip your fingers between the skin and breast meat of the bird, forming a pocket. Spoon some of stuffing into pocket. Spoon some of the stuffing loosely into the neck cavity. Pull neck skin to back; fasten with a small skewer. Lightly spoon the remaining stuffing into the body cavity. Tuck drumsticks under the band of skin that crosses the tail. If there is no band, tie drumsticks to the tail. Twist the wing tips under the chicken.
Place stuffed chicken, breast side up, on a rack in a shallow roasting pan. Insert a meat thermometer into the center of one of the thigh muscles. The bulb should not touch the bone. Roast, uncovered, in a 325 degree F oven for 1-3/4 to 2-1/2 hours or until meat thermometer registers 180 degrees F to 185 degrees F. At this time, chicken is no longer pink and the drumsticks move easily in their sockets. When the bird is two-thirds done, cut the band of skin or string between the drumsticks so the thighs will cook evenly.
Remove chicken from oven and cover it with foil. Let stand 10 to 20 minutes before carving. Makes 10 servings.