Cook the Mushrooms: Melt 2 tbsp butter in a pan over medium-high heat. Add mushrooms and cook until their liquids evaporate, about 10–15 minutes. Set aside.
Prepare the Vegetables: In the same pan, melt 1 tbsp butter. Add onions, carrots, and celery, cooking until tender, about 8–10 minutes.
Add Flavors: Stir in garlic and thyme, cooking 1 minute until fragrant.
Combine Ingredients: Pour in chicken broth. Add wild rice, cooked chicken, and sautéed mushrooms. Bring to a boil, then reduce heat and simmer covered for 20–30 minutes, until rice is tender.
Finish the Soup: Stir in milk or cream and Parmesan. Cook until creamy. Season with salt and pepper to taste.
Serve: Ladle into bowls and enjoy hot.
Serving and Storage Tips:
