Step 1

Rinse and dry the fresh mushrooms, or wipe the surface with a damp paper towel. Trim the stems and cut them into ¼-inch thick slices.

Step 2

Heat a large pot or dutch oven over medium-low heat. Add the butter. Once melted, add the onions. Saute until lightly brown and translucent, about 6 to 7 minutes. Add the minced garlic and thyme, saute for 30 seconds.

Step 3

Increase the heat to medium. Add the slicd mushrooms, sprinkle with salt and pepper. Saute until tender and most of the moisture releases, occasionally stirring, about 6 to 7 minutes. Reserve ¼ cup of for garnish.

Step 4

Add the wine and vinegar, stir and cook until most of the liquid evaporates, about 3 to 4 minutes. Add the dried porcini mushrooms, stir to combine.

Step 5

Add the vegetable stock and bring to a boil over high heat. Reduce the heat to low, cover, and simmer until mushrooms are tender, about 15 minutes, stirring every five minutes.

Step 6

Carefully transfer the soup to a blender and reserve the pot. Make sure the cap in the feeding hole is removed, and cover instead with a kitchen towel to prevent splattering. Do not fill the blender more than halfway full, work in batches if needed. Puree on medium speed for 30 seconds. Increase to high speed, process until a smooth, about 1 minute. Transfer the pureed soup back to the pot.

Step 7

Heat the soup over low heat. Add the cream and stir to combine. Continue to stir and cook until hot, about 4 to 5 minutes. Season with salt and pepper to taste.

Step 8

Divide the soup among serving bowls. Garnish with reserved mushrooms and chives.