Creating the Swiss Mushroom Melt is straightforward if you follow these simple steps:

1. Prep the Ingredients: Slice the mushrooms, mince the garlic, and chop the thyme.
2. Sauté the Mushrooms: In a large skillet, melt 2 tablespoons of butter over medium heat. Add the sliced mushrooms and garlic. Cook for about 5-7 minutes until the mushrooms are tender and golden.
3. Season: Add thyme, salt, and pepper to the mushroom mixture. Stir well and remove from heat.
4. Prepare the Bread: In another skillet, melt the remaining 2 tablespoons of butter. Toast the slices of bread on both sides until golden brown.
5. Assemble the Sandwiches: Spread Dijon mustard on one side of each slice of toasted bread (if using). Top two slices with the sautéed mushrooms and a generous amount of shredded Swiss cheese.
6. Top and Grill: Place the remaining slices of bread on top, pressing down gently. Return the sandwiches to the skillet and cook over medium heat. Grill each side for about 3-4 minutes, or until the cheese is melted and the bread is crispy.
7. Serve: Remove from the skillet and let cool slightly. Cut the sandwiches in half and sprinkle with fresh parsley for garnish.

These steps will guide you in creating an incredible Swiss Mushroom Melt effortlessly.