Sauté Aromatics: Melt 4 tablespoons unsalted butter in a large heavy Dutch oven or soup pot over medium heat. Add diced onion, shredded carrots, and chopped celery. Sauté for 4 to 5 minutes until vegetables are softened and onions are translucent. Stir in minced garlic and cook for 60 seconds until fragrant.

Build Velvety Roux: Sprinkle 1/4 cup flour evenly across the sautéed vegetables. Stir continuously with a wooden spoon for 1 to 2 minutes to cook out the raw flour starch without browning.

Simmer Broth & Chicken: Gradually pour in chicken broth while whisking constantly to create a silky, lump-free base. Whisk in half-and-half, dried thyme, oregano, nutmeg, salt, and black pepper. Submerge raw chicken breasts into the liquid. Bring to a gentle simmer, cover, and cook for 12 to 15 minutes until chicken registers 165°F (74°C) internally. (If using rotisserie chicken, simply add shredded meat directly).

Shred Chicken & Add Gnocchi: Transfer cooked chicken to a cutting board, shred into bite-sized pieces with two forks, and return to the simmering pot. Drop in 16 oz potato gnocchi. Simmer uncovered over medium heat for 3 to 4 minutes until gnocchi float to the surface and become tender and pillowy.

Wilt Spinach & Melt Parmesan: Lower heat to low. Stir in chopped fresh baby spinach and freshly grated Parmesan cheese. Simmer gently for 1 to 2 minutes until spinach is wilted and cheese is melted smoothly into the velvety broth.

Garnish & Serve Warm: Ladle hot soup into wide bowls. Garnish with freshly grated Parmesan cheese and cracked black pepper. Serve warm alongside crusty garlic breadsticks!