In a large cast iron pot or heavy-bottomed braising pan over medium-high heat, cook the bacon until crisp and fat is rendered. Remove bacon and drain on paper towel. Set aside.
Add pork to the pan with the bacon fat and cook on medium to high heat until pork is browned on all sides, about 5 to 6 minutes. Add the sausage, onions, and bell pepper. Cook until onions are translucent. Next add the chicken, celery, and garlic, parsley, and 3/4 cup chopped green onions. Cook until chicken is cooked through, about 5 to 7 more minutes. Add the cayenne and season with salt and pepper, to taste. Stir in the water, cover and let sit for 1 hour.
Cut bread lengthwise and place in oven to toast lightly.
Spoon some of the pork mixture on the bread bottoms, top each with slices of cheese, the reserved bacon and the remaining green onions and finish with the bread tops. Serve immediately.