Mushroom mixture: In a pan over high heat with a drizzle of oil, add in the mushrooms. Allow the mushrooms to brown while releasing its water and soften. Season with salt and pepper, then add in the thyme and white wine. Deglaze and allow the alcohol to evaporate. Add in the cream and continue to cook for 1-2 minutes until the sauce is thick. Set aside to cool
Miso Garlic Butter: in a bowl, combine all the ingredients for the miso garlic butter and set aside.
Assemble: spread the miso garlic butter onto your bread and layer on the brie cheese slices. Place it under the broiler for 5-10 minutes or until golden brown and the cheese is melted. Place the mushroom mixture on top, followed by the grated parmesan cheese and parsley. Slice and enjoy!