Preheat your oven to 350ºF. This ensures that when you place your beautiful peppers inside, they will cook evenly and become tender.
Prepare the peppers: Take your bell peppers and remove the top one inch, discarding the stem. With a knife, slice any usable pieces from the top and set them aside. Carefully scrape out the ribs and seeds, making sure to keep the pepper intact. This is your vessel for deliciousness!
Place the prepared peppers upright in a baking dish. They should stand tall and proud, waiting to be filled with savory goodness.
In a large skillet, heat the oil over medium heat. Once it's hot, toss in the finely diced mushrooms. Cook these until all the moisture has been released, which should take around 5 to 7 minutes. You'll notice a nice, earthy aroma filling your kitchen.
Add the diced onion and minced garlic to the skillet. Cook them together until the onions start to soften, about 5 minutes. This combination creates a fragrant base for your filling.
Now, it’s time to add the ground turkey (or beef). Cook this until there's no pink left, breaking it up with a spatula. This step is crucial for ensuring your filling is fully cooked and flavorful.
Once the meat has browned, stir in the diced tomatoes, Italian seasoning, salt, pepper, and red pepper flakes. Mix in the fresh spinach and the chopped pepperoni. Stir everything together until well combined. Taste and adjust seasoning if needed. This filling should be bursting with flavor!
Carefully spoon the hearty mixture into each prepared pepper, pressing down gently to pack them in. Make sure to fill them generously!
Pour one cup of water into the bottom of the baking dish. This helps steam the peppers, making them tender during baking.
Cover the dish with foil and bake in the preheated oven for about 40 minutes, or until the peppers are tender. You’ll know they’re ready when they have softened without losing their shape.
Remove the foil and preheat the broiler. Sprinkle the shredded mozzarella cheese generously over the tops of the peppers. Place them under the broiler for about 3 minutes until the cheese is bubbly and golden brown. This is where the magic happens!
Once done, remove from the oven and let them cool slightly. You can serve them immediately or allow them to cool completely for meal prep. The choice is yours!
