Roasted mushroom soup is a delightful twist on the classic mushroom soup. The roasting process intensifies the flavors of the mushrooms, resulting in a rich and earthy soup. To make this soup, start by tossing sliced mushrooms with olive oil, salt, and pepper, then spread them out on a baking sheet. Roast the mushrooms in the oven until they are golden brown and caramelized. In the meantime, sauté onions and garlic in a pot until softened. Add the roasted mushrooms, vegetable or chicken broth, and simmer until the mushrooms are tender. Finally, blend the soup until smooth and season with salt and pepper to taste. Serve this roasted mushroom soup with a drizzle of truffle oil for an extra touch of luxury.