Combine the flour and spices together in a large sandwich bag, set aside. Place the chicken breasts on a cutting board. Allow a few inches of space between each breast and cover with clear plastic wrap. Using meat malt, pound the breast to an even thickness (about 1/2 inch thick). Remove the clear wrap and cut the chicken into strips, about 3 strips per breast. Place the strips into the bag of flour and seasonings, seal and shake the bag.
Heat a large saute pan over medium heat with the oil. Place the chicken (don't crowd the pieces and cook in batches adding oil as necessary) into the pan and allow cook for 2 to 3 minutes each side. The chicken should be golden in color when you flip them over. Remove the cooked chicken from the pan and place on a plate with a paper towel to catch any excess oil.
Turn the oven to the "broil" setting. In a small bowl combine the mayonnaise, ketchup, prepared horseradish and yellow mustard; mix together. Cut the French bread in half both horizontally and vertically. Spread the Po'boy sauce on both sides of the loaf; set aside the top half. To the bottom add the chicken (overlapping pieces), then the bacon, avocado and Swiss cheese. Place that half on a baking sheet. Broil just until the cheese has melted and remove from oven.
Top the Po'boy with lettuce and tomatoes. Add the top half of the French bread. Cut into portions and serve immediately.