In a large pot or Dutch oven, heat the extra virgin olive oil over medium heat. Add the diced onions, carrots, and celery. Sauté for about 5-7 minutes, until the vegetables are softened and the onions become translucent.
Stir in the minced garlic, dried basil, kosher salt, and ground black pepper. Cook for an additional minute until fragrant.
Sprinkle the all-purpose flour over the sautéed vegetables and stir to combine. This will help thicken the soup slightly.
Gradually add the low sodium chicken broth, stirring constantly to avoid lumps. Bring the mixture to a gentle boil.
Add the boneless, skinless chicken breasts to the pot. Reduce the heat and let it simmer for about 15-20 minutes, or until the chicken is cooked through and reaches an internal temperature of 165°F (74°C).
Remove the chicken breasts from the pot and shred them using two forks. Return the shredded chicken to the pot.
Stir in the uncooked whole wheat orzo and let it simmer for about 8-10 minutes, or until the orzo is al dente.
Add the chopped spinach, fresh lemon juice, and chopped dill to the pot. Stir well and let it cook for another 2-3 minutes until the spinach is wilted.
Taste and adjust the seasoning if necessary. Ladle the soup into bowls and enjoy your warm, comforting Lemon Chicken Orzo Soup!