Melt 2 tablespoons of butter in a large Dutch oven or heavy soup pot over medium-high heat. Add sliced mushrooms, carrots, celery, and onion. Sauté for 6 to 8 minutes until vegetables soften and mushrooms turn golden brown.

Add minced garlic, chopped fresh thyme, and rosemary. Cook for 60 seconds until delightfully fragrant.

Pour in the rinsed wild rice and 5 cups of vegetable broth. Season with sea salt and cracked black pepper. Bring to a rolling boil over high heat.

Reduce heat to low, cover the pot tightly with a lid, and simmer gently for 30 to 35 minutes until the wild rice grains are tender and have burst open slightly.

While soup simmers, melt the remaining 2 tablespoons of butter in a small saucepan over medium heat. Whisk in the flour and cook for 1 minute to create a light golden roux. Slowly whisk in the heavy cream until smooth and slightly thickened.

Uncover the Dutch oven and pour the warm cream roux mixture directly into the simmering soup, stirring continuously. Simmer uncovered for 3 to 5 minutes until the soup attains a rich, velvety consistency.

Ladle into warm rustic ceramic bowls. Garnish with cracked black pepper and fresh sprigs of thyme. Serve piping hot with crusty sourdough bread.