Preheat oven to 325 degrees F. Line a large cookie sheet with aluminum foil.
Slice bread in half lengthwise. Slice green Manzanilla olives crosswise into approximately 1/8-inch slices.
In a large bowl, mix together the remaining ingredients. Spread desired amount of topping mixture over top of each half of bread.
Bake at 325 degrees F for 25-30 minutes, or until cheese is melted and bubbly and just beginning to brown.
Garnish with additional sliced green onion if desired.