Preheat the oven to 325 degrees F.
Combine the butter, mayonnaise, jalapenos, Cheddar, pepper Jack, olives, green chiles and green onions in a mixing bowl. Stir together until thoroughly combined.
Spread the mixture onto the French bread and put the bread on a baking sheet. Bake until the cheese is melted and browning, 20 to 25 minutes.
The mixture can also be refrigerated for up to 2 days and used as a dip.