Place the chicken breasts at the bottom of a 6-quart slow cooker. Scatter the diced onion, celery, matchstick carrots, and minced garlic around the chicken.

Pour the chicken broth over the ingredients. Sprinkle evenly with dried thyme, oregano, ground nutmeg, sea salt, and black pepper. Stir gently.

Cover with lid and cook on LOW for 6 to 7 hours or on HIGH for 3 to 4 hours, until the chicken is exceptionally tender and easily flakes with a fork.

Transfer cooked chicken breasts to a cutting board and shred using two forks into bite-sized tender strands. Return shredded chicken to the slow cooker.

In a small skillet on the stovetop, melt the 4 tablespoons of butter over medium heat. Whisk in the flour and cook for 1 to 2 minutes until bubbly and lightly golden (to cook off raw flour taste). Gradually whisk in 1 cup of warm broth from the slow cooker until smooth and thickened, then stir this mixture directly back into the crockpot.

Turn the slow cooker setting to HIGH. Add the potato gnocchi directly into the bubbling soup. Cover and cook on HIGH for 30 to 45 minutes until the gnocchi are tender, plump, and pillowy.

Stir in the heavy whipping cream, grated Parmigiano-Reggiano cheese, and chopped baby spinach. Stir continuously for 2 to 3 minutes until the spinach is wilted and the broth turns rich, velvety, and glossy.

Ladle piping-hot, creamy soup into deep bowls. Generously garnish with extra shaved parmesan ribbons, freshly cracked black pepper, fresh thyme leaves, and a light swirl of extra virgin olive oil. Serve with warm garlic breadsticks!