Roughly chop both the black olives and pimiento-stuffed green olives. Slice the green onions into thin pieces.
Combine the butter, mayonnaise, cheese, olives and spring onions in a mixing bowl. Stir together until thoroughly combined.
Spread the mixture onto the French bread. Bake until the cheese is melted and browning, 20 to 25 minutes.
Cook's Note: The mixture can also be refrigerated (up to 2 days) and used as a dip. Great with crackers!