In a large pot, melt the butter over medium heat.
Once melted, add in the all-purpose flour and whisk until combined. Cook for 1-2 minutes or until the mixture begins to bubble and thicken.
Slowly pour in the chicken broth while stirring continuously. Bring to a boil and then reduce heat to low and simmer for 15 minutes.
Add in the cooked chicken, salt & pepper, garlic powder, Italian dressing mix, milk, lemon juice, and white wine. Stir to combine and simmer for additional 10-15 minutes until thickened.
Stir in the parsley and cooked rice then season with additional salt & pepper if desired.
Serve hot.