Start by heating olive oil and butter in a large skillet over medium heat. I like to let the pan get hot before adding mushrooms so they brown instead of steaming. Spread them out in a single layer and cook until golden, then add garlic and thyme for aroma.
While the mushrooms cook, bring a pot of salted water to a boil. Drop in the gnocchi and cook until they float to the surface, which usually takes just a few minutes. Drain them gently and set aside so they keep their soft texture.
Lower the skillet heat and pour in the heavy cream, stirring gently to combine with the mushrooms. Add goat cheese in small pieces so it melts evenly into the sauce. Stir until smooth and creamy without letting it boil.
Add the cooked gnocchi directly into the skillet and toss gently so every piece is coated in sauce. Season with salt and black pepper, then sprinkle in Parmesan if using. Let everything simmer briefly so flavors come together.
Turn off the heat and garnish with fresh parsley. I always taste one last time here to adjust seasoning. Serve warm while the sauce is perfectly creamy and glossy.