Step 1

In a large saucepan, heat the extra-virgin olive oil over medium heat. Once hot, add the sliced celery, chopped carrots, and onions. Sauté for approximately 2 minutes or until the vegetables begin to soften, stirring occasionally.

Step 2

Add the sliced button mushrooms to the saucepan. Cook for about 5 minutes, stirring regularly, until the mushrooms release their liquid and most of it has evaporated, allowing their earthy flavors to intensify.

Step 3

Sprinkle the flour over the vegetable mixture, followed by the ground pepper and salt. Stir continuously for 2 minutes, ensuring the flour evenly coats the vegetables and begins to cook. This process will thicken the soup.

Step 4

Gradually pour in the vegetable broth, scraping up any browned bits from the bottom of the saucepan to enrich the flavor. Bring the mixture to a boil, then allow it to simmer, stirring occasionally, until slightly thickened, about 2 minutes.

Step 5

Stir in the cooked wild rice, heavy cream, lemon juice, and fresh parsley. Continue to cook the soup over medium heat for another 2 minutes, allowing the flavors to meld and the soup to heat thoroughly. Serve hot and enjoy.