Preheat the oven to 400°F.

Place mushrooms stem side down on a baking pan. Bake for 10-15 minutes or until the water leaks out of them. Remove from the oven and soak up the excess water then set aside.

In a skillet heat 2 tablespoons olive oil over medium heat. Add onion and garlic and sauté until the onions become translucent.

Add in spinach and tomatoes; cook for a couple of minutes. 

In a separate skillet, cook 6 strips of bacon to your preferred crispiness.

In a large bowl mix cream cheese and 1 tsp dried oregano until smooth and creamy. Add in cooked vegetables and chopped bacon and mixed until well combined. Add salt and pepper to taste.

In a small bowl melt 4 tablespoons butter. Add breadcrumbs and Parmesan cheese and mix until it looks crumbly.

Stuff mushrooms with cream cheese mixture and sprinkle with breadcrumb mixture. 

Bake for 15-20 minutes or until golden.

Serve immediately.