Vegan Cream of Mushroom Soup

To prepare soup: Heat 1 tablespoon oil in a large pot over medium-high heat. Add 4 cups shiitake mushrooms, 4 cups baby bella mushrooms, onion (or shallot), celery, garlic, thyme and 1/2 teaspoon salt and cook, stirring occasionally, until tender, 7 to 10 minutes. Add sherry; increase heat to high and simmer, stirring often, until the sherry has evaporated, 2 to 3 minutes.

Add broth and bring to a simmer. Puree water and 1 1/2 cups walnuts in a blender until completely smooth, about 1 minute. Pour into the soup; return to a simmer. Reduce heat to medium-low and cook, stirring often, until the vegetables are very soft, about 5 minutes longer.

Meanwhile, prepare topping: Heat oil in a medium skillet over medium heat. Add mushrooms and cook, stirring often, until soft, about 2 minutes. Add walnuts and salt. Cook, stirring occasionally, until hot, about 1 minute more.

Puree the soup with an immersion blender or in a regular blender (in batches, if necessary) until very smooth. (Use caution when blending hot liquids.) Stir in vinegar and pepper.

Serve the soup topped with the mushroom-walnut mixture and chives.