The Best Stuffed Portobello Mushrooms (Baked Recipe)

Preheat the oven to 400 degrees Fahrenheit.
Wipe off the mushrooms to remove the dirt. You can use a paper towel or a damp clean kitchen towel. Remove the stems from the mushrooms by twisting them off and discarding them. Scrape out any dark gills to create more space for the stuffing.
Place the mushrooms on a 9x13 sheet pan lined with parchment paper. Set aside.
To a large sauté pan add 1 tablespoon of olive oil and heat over medium-high heat. Add spinach, red bell pepper, red onion, Italian seasoning, red pepper flakes, salt, pepper, and paprika. Sauté and for 5 minutes or until the spinach has wilted. In the last 30 seconds, add the garlic.
To the sauteed vegetables, add the parmesan cheese, cream cheese, sour cream, tomatoes, breadcrumbs, and parsley (reserve 1 tablespoon for the garnish). Stir for 1-2 minutes until fully incorporated and heated through.
Use a spoon to fill the mushroom caps with the mixture from the skillet.
Top with the mozzarella cheese.
Bake on a rack in the middle of your oven for 17 minutes or until the mushrooms start to become tender.
With a pastry brush baste the outside of the mushrooms with the remaining 1 tablespoon of olive oil. Bake for an additional 5 minutes.
Finally, turn the oven to broil on high for 1-2 minutes or until the tops are golden brown.
Garnish with fresh parsley (or fresh basil) and red bell peppers. Serve warm.