Toast the cornbread. Pre-heat oven to 350°F. Using a sharp knife, cut the cornbread into ~ ¾" cubes. Place cubes on a rimmed baking sheet and bake for 20-25 minutes until edges begin to turn golden brown.
Cook the Pancetta. While cornbread cubes are baking, heat a saute pan over medium heat. Add the pancetta and cook 8-9 minutes, stirring frequently. Using a slotted spoon remove the pancetta from the pan and drain on a plate lined with paper towels. Leave the cooking fat in the pan.
Saute the veggies. Add the onion and celery to the saute pan. Cook for 5 minutes, stirring frequently. Add the garlic and cook for an additional minute. Remove pan from heat.
When the cornbread is done toasting remove from oven. If serving the stuffing immediately reduce oven temperature to 250 degrees.
Make the stuffing. Add pancetta, onion and celery mixture, water chestnuts, tomatoes, parsley, dried spices to the pan and melted butter to the pan. Carefully mix all ingredients together. Slowly add the chicken broth, about a ½ cup at a time, mixing after each addition, until desired consistency is reached. For more crunchy stuffing you'll want to use about 1 ¼ to 1 ½ cups of broth. For chewier stuffing you'll use the entire 2 cups.
Bake the stuffing. Spoon the stuffing into a 13x9 (or larger) baking dish. Either cover tightly with aluminum foil and refrigerate until ready to bake or place in an oven heated to 250 degrees and bake for 20 minutes. Remove foil and bake for an additional 10-15 minutes. Serve immediately.