Add diced large onion, chopped celery stalks, and peeled and diced carrots. Cook for 5–7 minutes until the vegetables are softened.
Add minced garlic cloves and cook for 1 minute until fragrant.
Stir in chopped leftover turkey and medium head cauliflower cut into small florets.
Pour in turkey or chicken broth and add diced tomatoes, dried thyme, dried rosemary, salt, smoked paprika, black pepper, and bay leaf.
Bring the soup to a boil.
Reduce the heat and simmer for 20–25 minutes, or until the cauliflower is tender.
Add baby spinach and cook for 2–3 minutes until wilted.
Remove the soup from the heat and stir in fresh lemon juice.
Remove and discard the bay leaf.
Garnish with chopped fresh parsley if desired before serving.
Notes
For a thicker soup, you can puree 1-2 cups of the soup and stir it back into the pot.If you prefer cauliflower rice instead of florets, add it in the last 5 minutes of cooking to prevent it from becoming too mushy.I included chicken broth in the recipe but you can use turkey broth as well if you have any available.Refrigerate any leftovers in an airtight container for up to 5 days.