Cut pointed ends from bread, then cut into 1/2 inch slices this way: Make first cut almost through to bottom of loaf and second cut clear through; repeat (finished individual sandwiches will be separate this way).
Cream butter or margarine with horseradish mustard; spread generously between the hinged slices; place 2 folded slices of bologna in each sandwich, half in and half poking out.
Run two skewers (1 from each end) through bread to hold it together; place on a large piece of aluminum foil on cookie sheet; arrange sliced olives, then cubed cheese down center; bring foil up and around loaf and seal tightly.
Bake in moderate oven (350°) 20 minutes, or until heated through and cheese is melted.
Unwrap; remove skewers before serving.
Each sandwich will pull apart easily; serve hot.