Melt 2 tablespoons of unsalted butter in a large, deep skillet over medium heat. Add 1 cup sliced carrots, 1 cup diced celery, and 1 finely chopped yellow onion. Season with salt and sauté for 6–8 minutes until softened.

Stir in 1 cup quartered cremini mushrooms and 3 cloves minced garlic. Cook for another 5 minutes until tender and fragrant.

Sprinkle ¼ cup all-purpose flour over the sautéed vegetables, stirring constantly for about 2 minutes to coat.

Gradually whisk in 4 cups chicken stock and 1 cup whole milk, stirring continuously to prevent lumps. Simmer until thickened, about 3–4 minutes.

Stir in 2 tablespoons Dijon mustard, 1 tablespoon Italian seasoning, and nutmeg if using. Simmer for a couple of minutes.

Add 1 pound fresh potato gnocchi, stirring to submerge. Cook uncovered for 4–5 minutes until gnocchi is tender.

Fold in 2 cups torn cooked chicken and 1 cup sweet peas, simmer for an additional 3–4 minutes until heated through.

Tear in fresh thyme leaves and adjust seasoning with salt and pepper. Let sit off the heat for 5 minutes.

Serve warm, garnished with chopped parsley and grated Parmesan if desired.