Make perpendicular cuts very carefully along the bread's top. You can ask someone to hold it for you so it doesn't fall apart.
Put it in an oven dish with baking paper. Cut the cheese, feta cheese, butter and lard salami into thin pieces - the size of the cuts.
Cut the onions into round slices. Arrange the ingredients in the bread cuts, making sure there's a little bit of each of them everywhere.
Bake in a hot oven until reddened.