01 -
Heat olive oil in a stockpot or Dutch oven over medium-high heat. Add onion, celery, carrot, and garlic; sauté, stirring frequently, until vegetables begin to soften, approximately 3 minutes.
02 -
Stir in lemon zest, lemon juice, bay leaf, salt, and black pepper. Reduce heat to medium, cover, and continue cooking until vegetables are fully softened, about 3 minutes more.
03 -
Pour in chicken broth and add cauliflower rice. Increase heat to medium-high and bring mixture to a boil. Reduce heat to medium or medium-low and simmer, uncovered, until vegetables are very tender, 5 to 8 minutes.
04 -
Fold in shredded or diced chicken and cook, stirring, until chicken is warmed through. Serve the soup hot.