Melt butter in a medium pot over medium heat, add chopped onion and minced garlic. Sauté until onion is translucent, about 4-5 minutes.

Incorporate diced celery and sliced carrots. Continue to sauté for an additional 3 minutes until softened.

Pour in chicken stock and add shredded chicken with Italian seasoning. Bring to a boil, then simmer for about 20 minutes.

Remove chicken, stir in dry orzo pasta, and cook uncovered for about 10 minutes.

Shred cooked chicken and return to pot. Stir to combine.

Stir in lemon juice, parsley, dill, salt, and pepper to taste. Serve hot.