1 loaf Vienna bread, unsliced
3/4 lb. fresh mushrooms, sliced
3/4 lb. cubed Swiss cheese
1/2 lb. butter
1 tbsp. dry mustard
1 tbsp. season salt
4 tbsp. chopped onion

Melt butter and seasonings (including onion). Criss cross cut Vienna bread. Stuff mushrooms down into cuts then push cheese on top of mushrooms. Pour butter mixture over top of loaf.

Bake 350°F for 40 minutes on a cookie sheet.

Note: Put a sheet of foil under load and curve up edges to prevent leaks.