In a large Dutch oven, melt 3 tablespoons of unsalted butter over medium heat. Once it foams, add sliced mushrooms, chopped onion, and minced garlic, seasoning with kosher salt and freshly ground black pepper. Sauté for 5–7 minutes, stirring occasionally, until the onions become translucent and the mushrooms are tender and lightly browned.

Stir in 3 tablespoons of all-purpose flour with a wooden spoon, cooking for 1–2 minutes until it forms a roux. Gradually whisk in 6 cups of chicken stock to incorporate, ensuring there are no lumps. Add 2 boneless, skinless chicken breasts and a mix of dried oregano, rosemary, and thyme. Bring the mixture to a simmer, cooking for 20 minutes until the chicken reaches an internal temperature of 165°F.

Carefully remove the cooked chicken breasts from the pot and set them aside to cool slightly. Once cool enough to handle, shred the chicken into bite-sized pieces using two forks. Return the shredded chicken to the soup, stirring well to combine with the broth and veggies, ensuring a hearty texture.

Lower the heat to medium-low and pour in 1 cup of heavy cream, stirring continuously until fully incorporated for that creamy richness. Add 2 cups of cooked wild rice, mixing well to blend the flavors throughout the Creamy Mushroom Chicken and Wild Rice Soup. Allow the soup to warm through, about 5 minutes.

Ladle the steaming soup into bowls, and feel free to garnish with fresh thyme leaves or a sprinkle of black pepper for added flavor. Serve warm, pairing it with a slice of crusty bread or a fresh salad to enhance the comforting experience of this delightful soup.