Step 1

Melt 2 tablespoons butter in a medium-sized skillet over medium heat.

Step 2

Add sliced mushrooms and chopped onion.

Step 3

Sprinkle salt on the mushrooms and onions.

Step 4

Sauté until the onions have become transparent and the mushrooms have released their water.

Step 5

Add chopped garlic and sauté for 1 to 2 minutes.

Step 6

Transfer the mushrooms and onions to a medium-sized saucepan over medium heat.

Step 7

Add chicken broth and heat through.

Step 8

Use either a stick blender or food processor to process the soup until the mushrooms are chopped very fine.

Step 9

Add heavy cream and heat until the soup is warm.

Step 10

Add truffle oil just before serving.

Step 11

You may want to drizzle sour cream on the soup just before serving.