Preheat your oven to 375°F (190°C). Cook the wild rice blend in chicken broth according to the package instructions; once done, set aside.
In a large skillet, heat olive oil over medium heat. Add onion and garlic, sautéing until translucent.
Increase the heat to medium-high and add the chicken pieces to the skillet. Season with thyme, salt, and pepper. Cook until the chicken is browned and cooked through.
Stir in mushrooms and carrots; cook for another 5 minutes until the vegetables are tender.
Sprinkle flour over the chicken and vegetable mixture, stirring to coat. Gradually pour in the milk, stirring continuously as the mixture thickens to create your sauce.
Remove from heat and gently stir in the cooked wild rice, Parmesan cheese, and sour cream until everything is well combined.
Transfer the mixture into a greased casserole dish. If desired, sprinkle with slivered almonds or crispy bacon for a pleasant crunch.
Bake uncovered for about 25-30 minutes, or until the casserole is bubbly and the top gets a touch golden.
Let it sit for 5 minutes before serving to allow the flavors to meld and the sauce to set slightly.
