Heat a skillet over medium heat and add olive oil or butter, allowing it to melt and coat the bottom. Once hot, add the sliced mushrooms and sauté for 8-10 minutes until they turn golden brown and tender, releasing their savory juices. Incorporate the minced garlic and cook for an additional minute, stirring until fragrant.

Reduce the heat to low and add the softened cream cheese and sour cream to the skillet with the sautéed mushrooms. Stir constantly for 3-5 minutes, melting the cheese and blending it with the mushrooms until you achieve a smooth and creamy texture.

Gradually fold in half of the shredded mozzarella cheese along with the grated Parmesan cheese. Continue stirring for another 2-3 minutes until the cheeses are fully melted and evenly incorporated.

Sprinkle the remaining mozzarella cheese over the dip, ensuring an even layer. Carefully transfer the skillet to a preheated oven at 375°F. Bake for 15-20 minutes or until the dip is bubbly and the top is beautifully golden brown.

Once out of the oven, let the Stuffed Mushroom Dip cool slightly before garnishing with freshly chopped thyme or parsley. Serve hot with toasted bread, crackers, or veggie sticks.