Sara Deseran, co-founder of the San Francisco Bay Area’s Tacolicious restaurants as well as MF Chicken, a takeout rotisserie business, knows umpteen ways to use leftover chicken—and this zesty soup is one of our favorites. It’s especially good on busy weeknights when everyone in the family gets home at a different time: Set the pot on the counter with rice, toppings, and bowls on the side, for each person to heat and eat whenever. (After 2 hours, though, chill everything and direct the family to the fridge.)
*Fragile, lovely, and mild, you’ll find squash blossoms at farmers’ markets through summer and at some grocery stores. Or plant zucchini yourself. It’s a fun crop to harvest with kids, since it’s easy to grow and they’ll love picking the flowers.
Make stock: Pull meat off bones and dice enough to make 2 cups; set aside. Put bones in a 6-qt. pot and pour in 9 cups water (to just cover bones). Add celery, carrot, onion quarter, and bay leaf. Bring to a boil, then reduce heat and simmer, lid barely ajar, 2 hours. Strain stock and return to cleaned pot.
Add lime juice, salt to taste, chopped onion, zucchini, and corn. Bring to a simmer, then add 2 cups diced reserved chicken. Simmer until vegetables are just cooked, 1 to 2 minutes more. Taste and season with salt.
Put 1/3 cup rice in each of 4 bowls. Ladle soup over rice. Stem and halve squash blossoms (if using) and add to bowls. Top with some cheese and a grind of pepper.
MAKE AHEAD Soup through Step 2, up to 1 day. Cooked rice, up to 2 days.
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.