Meatball & Rice Soup with Spinach

This creamy, tart soup is my favorite. It is one of the first dishes I request when I visit my parents, especially in the winter months. I make it often, but it just seems to taste better when my mother makes it. Traditionally, the meatballs are dropped into the broth raw, but I found that roasting them first gives a richer flavor. You can make the meatballs a day ahead.