Preheat a large heavy-bottomed pot over medium-low heat, then add the butter. Once melted, add the carrots, celery, and onion, increase the heat to medium, and cook for 5 to 6 minutes or until slightly softened. If the onion starts to brown, reduce the heat.
Add the chicken stock and salt, cover the pot, increase the heat, and bring the soup to a boil. Reduce the heat and gently boil for 8 to 9 minutes to soften the vegetables, stirring occasionally.
Remove the lid and reduce the heat to medium. Once the liquid is no longer boiling hard, add the cream, stir well, and allow it to heat until steamy.
Add the baby spinach and stir until wilted, then add the chicken, gnocchi, and black pepper. Raise the heat slightly and simmer for 5 minutes.
Stir in the Parmesan cheese and lemon zest, taste the soup, adjust the salt and pepper as needed, then serve hot topped with extra grated Parmesan cheese.
Notes
For detailed ingredient notes, substitution tips, variations, and step-by-step photos, scroll through the full recipe post.
Use a digital kitchen scale for precise measurements and an oven thermometer to confirm your oven is heating correctly.
To switch to gram measurements, click "Metric grams" in the ingredients section of the recipe card.
Three cups of chicken is approximately the meat of one rotisserie chicken.
Don't omit the lemon zest if you can help it. The soup is delicious without it, but the lemon zest adds a bright note that takes it to the next level.
After adding the Parmesan cheese, taste the soup before adding more salt, as the cheese can make it saltier.
Storage
Store leftover soup in an airtight container in the refrigerator for up to 3 days. Reheat gently over low heat on the stovetop, stirring occasionally, until warmed through.