With a mortar and pestle, mash
anchovies, garlic, mustard, onions, and capers. Turn into a
mixing bowl and vigorously beat in olive oil (or combine these
ingredients in food processor or blender and blend until
anchovies are mashed).
Slice loaf of Italian bread lengthwise. Spread anchovy mixture
on top of one slice of bread. Lay slices of red pepper over
anchovy mixture. Sprinkle with parmesan cheese. Top with second
slice of bread.
Wrap in foil, place in preheated
400 oven for 10 minutes. Slice and serve.