Preheat your cooking system or flat top grill to medium high heat. Trim all silver skin from the backstrap and butterfly lengthwise. Do not cut into medallions.
Season with salt and pepper.
Chop bacon into ½ inch pieces.
Brown in a 12-inch cast iron skillet.
Add mushrooms and garlic. Once the mushrooms are cooked, remove from heat.
In a medium-size bowl, mix bacon, mushrooms, cream cheese and breadcrumbs.
Evenly add stuffing mixture to the butterfly-cut backstrap.
Close butterfly cut and tie off with butcher's twine. Brush with olive oil.
Grill over medium/high heat until the meat reaches medium rare. For the best taste and texture, be sure not to overcook.