Preheat oven to 400 degrees F.
In a large bowl, combine the turkey, beef, pork, eggs and breadcrumbs and fold ingredients until evenly combined.
In a large saute pan over medium-high heat, add olive oil and heat. Add the celery, peppers and mushrooms and saute until translucent. Remove from heat and allow to completely cool. Once cooled, add to meat mixture along with garlic powder, cumin and salt and pepper, to taste, and combine.
Place meat mixture into large loaf pan.
In another small bowl, combine the ketchup, soy sauce and brown sugar and smooth and slather onto meat mixture, reserving some for basting. Top with bacon slices, place into preheated oven and cook for about 1 hour or until the meatloaf registers 180 degrees F when an instant-read thermometer is inserted into the center.
Once the meatloaf is at 180 degrees F, remove from the oven, top with extra sauce and cheese slices and place back into oven just until the cheese melts. Remove from the oven, cut and serve.
Cook's Note: If the sauce and bacon on the top starts to get too brown, cover the loaf pan with a piece of aluminum foil.
