Step 1: Prepare the Mushrooms : Preheat your oven to 375°F (190°C). Clean mushrooms gently with a damp cloth and remove the stems. Set caps aside and finely chop the stems to include in the filling.

Step 2: Cook the Filling : Heat olive oil or butter in a skillet over medium heat. Add ground beef, chopped onion, garlic, and chopped mushroom stems. Cook until beef is browned and onions are soft. Drain excess fat if needed.

Step 3: Mix the Filling : Remove the skillet from heat and stir in breadcrumbs, grated Parmesan, Italian seasoning, paprika, salt, and black pepper. Mix until well combined.

Step 4: Stuff the Mushrooms : Spoon the beef mixture into the mushroom caps, pressing gently to fill each one generously but not overflowing. Place stuffed mushrooms in a lightly greased baking dish.

Step 5: Add Cheese Topping (Optional) : Sprinkle shredded mozzarella or cheddar on top of each stuffed mushroom if desired.

Step 6: Bake : Bake in the preheated oven for 20–25 minutes until mushrooms are tender and cheese is melted and lightly golden.

Step 7: Serve : Remove from oven and let cool slightly. Serve warm as an appetizer or main course. Garnish with fresh parsley if desired.