• Preheat the oven to 350 ℉.
• In a skillet oven medium-high heat, saute the onions, mushrooms, and green bell pepper until softened and golden brown, about 10 minutes.

  Set aside and let cool.
• In a large mixing bowl, combine ground beef, sourdough bread crumbs, egg, milk, cooled sauteed veggies, Worcestershire sauce, garlic powder, salt, and pepper.

  Mix well until all ingredients are fully combined.

Make the sauce

•  In a small bowl, whisk together the beef bone broth, ketchup, coconut sugar, and honey mustard until combined.

Layer the meatloaf

• Press half of the meat mixture into the bottom of a loaf pan.

  Next, lay 4 provolone cheese slices over the meat, leaving a border around the edges.

  Cover the cheese with the remaining meat mixture, pressing the edges to seal in the cheese.
• Pour the ketchup sauce over the top of the entire meatloaf and place in the oven for 1 hour.

  After 45 minutes of cooking, drain some of the drippings from the meat loaf and return to the oven for another 15 minutes.
• After the meatloaf has cooked for 1 hour, remove it from the oven and set the oven to broil.
• Top the meatloaf with the remaining slices of provolone cheese and return to the oven to broil for 5-8 minutes or until bubbly and the cheese has started to brown.

  Garnish with fresh or dried parsley (optional).
• Let the meatloaf rest for at least 5 minutes before slicing and serving.