Pat chicken breasts dry and season with salt and pepper. In a large skillet, melt 2 tablespoons of butter over medium-high heat. Add chicken and sear for 6-8 minutes. Transfer to a plate.

In the same skillet, add 1 tablespoon of butter, add chopped onion and celery, and sauté for 4-5 minutes. Stir in minced garlic and cook for another minute.

Add sliced mushrooms to the skillet and cook undisturbed for about 3-4 minutes until browned. Stir to combine.

Stir the mushroom mixture with 1.5 cups of wild rice and toast lightly for 2 minutes.

Pour in 4 cups of chicken broth and a splash of dry white wine. Bring to a boil, reduce heat to low, and simmer for 15-20 minutes.

In a separate saucepan, melt 2 tablespoons of butter. Whisk in 2 tablespoons of flour, then gradually add 1.5 cups of whole milk, whisking until thickened.

Mix the creamy sauce into the skillet with wild rice, nestle chicken on top. Preheat oven to 400°F and bake uncovered for 20-25 minutes.

Remove from oven, let rest for 10 minutes before serving. Garnish with parsley.