Chop green and black olives and green onions. Place butter, mayonnaise and cheese in bowl and stir. Add olives and onions and stir until well incorporated. Sliced French bread lengthwise. Spread mixture evenly onto both halves of bread. Bake on a cookie sheet at 325° for 25 minutes or until cheese is totally melted and the top is beginning to turn light brown. Cool for about 5 minutes and then slice thinly for appetizers.