2. Slice the bread in half lengthwise, then in half again crosswise so you wind up with 4 pieces. Scoop out the bread to remove the soft inner portion and discard. Place the bread scooped side up on a baking tray. Spoon 1/4 cup of sauce into each piece of bread. Lay a piece of chicken on top and cover with 1 cup of spinach leaves. Pour another 1/4 cup of sauce on top of the spinach, then sprinkle each sandwich with 1/4 cup of mozzarella and 1 tablespoon of Pamesan.
3. Broil until the sandwich is wilted and the cheese is bubbly and browned, 4-5 minuets.