Melt half the butter and heat half the oil in a large pot. Add half of the mushrooms, salt, and pepper. Cook until golden.
Saute onion, garlic, carrot, celery, remaining mushrooms, thyme, and sage in the same pot.
Add wild rice, stock, bay leaves, salt, and pepper. Simmer for 30-35 minutes.
Whisk flour and ¼ cup cream until smooth. Add remaining cream and pour mixture into soup.
Cook for 5 minutes until thickened. Add parmesan.
Reheat mushroom topping. Ladle soup into bowls, top with mushrooms and fresh thyme to garnish. Serve with crusty bread.
