In a large skillet, melt butter on medium heat and add mushrooms. Cover with lid and cook for about 3 minutes.
Place the bread in the toaster, or preheated oven, and let it brown slightly.
Take the lid off the mushrooms, add paprika and keep cooking for about 2 more minutes, or until all the liquid evaporates. Season the mushrooms with salt and truffle oil and add the cheese on top. Stir the mushrooms with cheese, cover with tight lid and turn off the heat.
While the cheese is melting, return to the bread. Cut the garlic clove in the middle, and rub the browned bread with garlic.
Place the bread on a serving platter and scoop the cheesy mushrooms on top. Enjoy!