Sear the Seasoned Chicken: Heat 1 tablespoon of olive oil in a large 5- to 6-quart enameled Dutch oven or soup pot over medium heat. Season the diced chicken with 1/2 teaspoon salt and 1/4 teaspoon black pepper. Add the chicken to the pot in a single layer and cook for 4 to 5 minutes until lightly golden on all sides (it does not need to be cooked completely through yet). Transfer the chicken and any pan juices to a clean plate.

Build the Mirepoix Base: Lower the heat to medium-low and melt 2 tablespoons of butter in the same pot, scraping up any browned bits left by the chicken. Add the diced onion, sliced carrots, and celery. Sauté for 6 to 7 minutes until the vegetables soften and begin to sweeten. Stir in the minced garlic, chopped thyme, and rosemary; cook for 1 minute until fragrant.

Form the Roux: Sprinkle 3 tablespoons of all-purpose flour evenly over the sautéed vegetables. Stir continuously with a wooden spoon for 1 to 2 minutes to coat the aromatics and cook off the raw flour flavor.

Add Broth & Wild Rice: Gradually pour in 6 cups of chicken broth, whisking constantly to dissolve the flour and prevent lumps. Stir in the rinsed wild rice blend, dried bay leaf, remaining 1/2 teaspoon salt, and 1/4 teaspoon pepper. Return the seared chicken and juices to the pot.

Simmer until Tender: Bring the soup to a gentle boil over medium-high heat. Once bubbling, immediately reduce the heat to low, cover the pot with a tight-fitting lid, and let it simmer gently for 20 to 22 minutes, stirring once or twice, until the wild rice grains burst tenderly and the chicken is cooked through.

Stir in Cream & Finish: Remove the lid and discard the bay leaf. Turn off the heat. Slowly pour in the room-temperature heavy cream and grated Parmesan cheese, stirring gently until the soup turns silky and velvety. Stir in 1 tablespoon of fresh lemon juice to lift the rich savory flavors. Taste and adjust with a pinch of sea salt or black pepper if desired.

Plate & Serve: Ladle the steaming soup into warm ceramic bowls. Garnish each bowl with chopped fresh parsley, an extra turn of freshly cracked black pepper, and serve warm with slices of crusty sourdough bread.