Rinse the wild rice blend in a fine mesh strainer under cold water for about 30 seconds, then set aside.
Dice the onion, slice the carrots, dice the celery, and mince the garlic. Set all prepped vegetables aside.
Season the chicken with salt and pepper. Heat olive oil in a large Dutch oven over medium-high heat and sear the chicken for 4-5 minutes per side until golden brown. Remove to a plate.
Reduce heat to medium, melt butter in the same pot, then add onion, carrots, and celery. Sauté for 6-8 minutes until onion is soft. Add garlic and cook for 1-2 minutes more. Stir in thyme, rosemary, sage, onion powder, and garlic powder.
Sprinkle flour over the vegetables and stir to coat. Cook for 1-2 minutes, stirring constantly, to make a roux.
Slowly pour in the chicken broth, about 1 cup at a time, stirring well after each addition to prevent lumps. Season with salt and pepper, then stir in the rinsed wild rice. Return the seared chicken to the pot.
Bring to a gentle boil, then reduce heat to low, cover, and simmer for 40-45 minutes, stirring occasionally, until the rice is tender and chicken is cooked through.
Remove the chicken from the pot and shred it with two forks, then return the shredded chicken to the soup.
Reduce heat to low, pour in the heavy cream, and stir gently. Heat through for 3-5 minutes without boiling. Adjust seasoning with salt and pepper to taste.
Ladle the soup into bowls, garnish with fresh parsley if desired, and serve immediately with crusty bread or dinner rolls.