In a large pot, melt the butter over medium-low heat. When melted, add the celery, onion, carrot & garlic. Cover and reduce heat to low and cook for approximately 8-10 minutes until vegetables begin to soften.
Add the chicken broth, water and increase heat to medium-high and bring to a boil. When broth boils, add salt (to taste), pepper and nutmeg. Stir to combine. Reduce heat to low and add tortellini. Simmer until tortellini cooks to al dente.
Once cooked, remove the rind, and add the baby spinach. Stir to combine. Garnish with freshly grated Parmigiano Reggiano.
Recipe by Chef Tom Cooks ! at http://cheftomcooks.com/2015/12/15/spinach-tortellini-soup/