Pre-heat oven to 400 degrees F. Grease a baking tray well with cooking spray and set aside.
Remove mushroom stems.
Make sure all the mushroom caps can stand up on their own. If not, slice a bit off the tops with a small knife till sturdy.
Arrange all the mushroom caps on the prepared baking tray with the de-stemmed side up and ready to stuff.
In a large sauté pan on medium heat fry the bacon until brown and crispy, about 6 minutes.
Add the oil into the pan along with the minced mushroom stems, onions, garlic, bell peppers and a bit of salt and pepper. Stir well and sauté until the veggies soften, about 3 minutes, stirring frequently.
Once softened turn off the heat and let cool slightly.
In a medium mixing bowl add in the bread crumbs, parmesan, Italian mix and a bit of pepper. Stir well to combine.
Add the warm bacon and mushroom filling into the bread crumb mixture and stir well to combine.
Stuff each mushroom cap with a bit of the filling, pressing it down firmly as you go to secure the filling.
Bake at 400 degrees F. for 15 to 20 minutes until the tops are golden brown. Serve on a platter or tray and garnish with a sprinkling of chives. Serve warm.