Soak cashews in water for at least 30 minutes, or boil for 15 minutes.

Heat olive oil in a large pot over medium heat. Add mushrooms and cook until softened, about 5-7 minutes.

Add vegetable broth, nutritional yeast, salt, and pepper to the pot. Bring to a boil.

Reduce heat and simmer for 10 minutes.

Drain cashews and add them to the pot. Blend with an immersion blender until smooth and creamy.

In a small bowl, whisk together cornstarch and 2 tablespoons of water. Add to the pot and cook until thickened, about 1-2 minutes.

Serve hot.