Heat the olive oil in a large soup pot or Dutch oven over medium-high heat. Add the chicken, lemon pepper seasoning (optional), Italian Seasoning, salt and pepper to taste, and cook until browned on all sides, about 4-5 minutes.
1 teaspoon olive oil, 20-24 oz boneless, skinless chicken breasts or thighs, ½-1 teaspoon Italian Seasoning, ½ teaspoon lemon pepper seasoning, salt to taste
Remove the chicken and set it aside. Leave the chicken drippings in the pot for flavor.
In the same pot, add the onions, carrots, celery, and garlic and cook until translucent, about 3-4 minutes.
½ cup diced onions, ½ cup diced celery, ½ cup diced carrots, 2-3 garlic cloves
Sprinkle the flour throughout and stir well to combine. Add the flour in stages to avoid excess drying.
3 tablespoons all purpose flour
Gradually whisk in the chicken broth, lemon juice, and lemon zest. Stir repeatedly, ensuring there are no lumps. Deglaze the bottom of the pan using your spoon. Leave the brown spots you scoop up in the pot. These will provide flavor from the cooked, seasoned chicken. 6 cups chicken broth, 2 tablespoons fresh lemon juice, 1 teaspoon lemon zest
Bring the mixture to a rolling boil and add in the cooked chicken to the pot. Cover the pot with the lid and lower the heat to low to let the soup simmer for 15 minutes.
Remove the lid from the pot and add to the orzo. Allow it to cook on low heat (without the lid on the pot) for about 10 minutes or for however long it takes for the orzo to become al dente.
1 cup dry orzo
Taste the soup repeatedly and adjust the spices as necessary to suit your taste. Cool before serving.