1. Heat the olive oil in a large pot or Dutch oven over medium heat. Add the chopped yellow onion, diced carrots, and diced celery. Cook, stirring occasionally, for 5-7 minutes until the vegetables start to soften and the onion becomes translucent. This step builds the flavor foundation for your soup.

2. Stir in the minced garlic and cook for another minute until fragrant. Be careful not to burn the garlic, as it can turn bitter quickly.

3. Carefully pour the chicken broth into the pot. Bring the mixture to a rolling boil over medium-high heat.

4. Once the broth is boiling, add the orzo pasta. Reduce the heat to medium-low and simmer for 8-10 minutes, or until the orzo is al dente (tender but still firm to the bite). Stir occasionally to prevent the pasta from sticking to the bottom of the pot.

5. Stir in the shredded or diced cooked chicken and the fresh lemon juice. Continue to simmer for another 2-3 minutes, allowing the chicken to heat through and the flavors to meld.

6. Remove the pot from the heat. Stir in the fresh chopped parsley. Taste the soup and season generously with salt and black pepper as needed. The amount will depend on the saltiness of your chicken broth.

7. Ladle the hot soup into bowls and serve immediately. A little extra fresh parsley or a lemon wedge for garnish can add a nice touch.