01 -
In a large Dutch oven, heat the oil over medium heat. Add the carrots, celery, onion, basil, salt, and pepper. Let cook until the vegetables soften and are beginning to brown, about 8 minutes.
02 -
Add the garlic and cook, stirring constantly, until fragrant, about 30 seconds.
03 -
Sprinkle the flour over the top and stir until it disappears. Pour in 6 cups of the chicken broth and stir to combine until the flour is completely dissolved.
04 -
Carefully lower the chicken into the broth. Bring the soup to a boil, then reduce the heat, partially cover the pot, and let gently simmer for 10 to 15 minutes, until the chicken is cooked through and reaches 165°F on an instant-read thermometer.
05 -
Remove the chicken to a cutting board and cover. Let rest for at least 5 minutes.
06 -
Return the soup to a simmer, then stir in the orzo. Simmer for 7 minutes, stirring periodically to prevent sticking, until the orzo is very al dente.
07 -
Dice or shred the chicken, then add it to the pot.
08 -
Stir in the spinach, lemon juice, and dill. Add additional chicken broth if needed to achieve your desired consistency. Simmer 3 to 5 minutes until the spinach wilts and the orzo is al dente. Adjust seasoning with salt and pepper as necessary. Serve warm.