Using the sauté pan heat the oil over medium high heat. Add the mushrooms and cook for 5 minutes until they start to soften. Add the spinach, salt, garlic, and pepper. Cook until the spinach has wilted. Add the cream cheese and mix until it evenly coats the mushrooms and spinach. Remove from the heat and stir in the rest of the cheese and set aside.
Slice a pocket into each chicken breast and fill with ¼ of the spinach and mushroom mixture.
Wrap each breast in about 5 slices of bacon and place the seam side of the bacon onto the baking rack. Bake for about 30 minutes or until the largest part of the chicken reads 165°F or 74°C.