1. Begin by heating a large skillet over medium heat. Melt the unsalted butter and olive oil together, then add the minced garlic. Sauté the garlic for 30 seconds, just until fragrant.

2. Next, add the sliced mushrooms, salt, pepper, and dried thyme. Cook the mushroom mixture for 5-7 minutes, stirring occasionally, until the mushrooms are tender and golden brown. Remove the skillet from the heat and set aside.

3. Preheat your oven to the broil setting on high. Line a baking sheet with parchment paper.

4. Place the slices of crusty bread on the prepared baking sheet. Evenly distribute the sautéed mushroom mixture over each slice of bread. Generously sprinkle the shredded mozzarella cheese and grated Parmesan cheese over the top of the mushrooms.

5. Slide the baking sheet into the preheated oven and broil the toasts for 3-5 minutes, or until the cheese is melted, bubbly, and lightly golden in spots. Keep a close eye on them to prevent burning.

6. Once the Gourmet Cheesy Mushroom and Garlic Toasts are hot and melty, remove them from the oven. Sprinkle the chopped fresh parsley over the top, if desired, for a pop of color and freshness. Serve these irresistible toasts warm.