In a large saucepan or Dutch oven melt the butter over medium heat. Add the onions, celery, carrot to the pot and cook for about 5 minutes until the vegetables soften.
Add the chicken thighs to the pot and season everything with salt and pepper. Cook for another 5 to 7 minutes or until the chicken is no longer pink.
Sprinkle the flour over the chicken and vegetables and stir. Cook for a minute then add the rosemary, white wine, chicken broth and the pasta. Stir everything together and adjust for seasoning as necessary with salt and pepper.
Cook for 15 minutes over medium low heat, stirring occasionally, then add the frozen peas. Stir everything together and cook for an additional 5-10 minutes or until the pasta is cooked to your liking.
Garnish with fresh parsley and serve.
