In a large pot or Dutch oven melt butter over medium high heat.
Add the onion to the pot and cook for 2-3 minutes, stirring occasionally. Add the garlic, carrots, celery, parsley, salt and pepper to the pot and stir to mix. Continue to cook the vegetables for 4-5 minutes, or just until the vegetables start to soften.
Add the concentrated low sodium chicken flavor to the vegetables and stir to mix.
Slowly sprinkle the flour over the vegetables and stir everything together until completely combined. Allow vegetables to cook for 1-2 minutes before slowly pouring in the chicken broth, stirring the entire time to prevent the flour from clumping.
Reduce heat to medium and bring the soup to a simmer. Partially cover the pot with the lid and simmer for approximately 10-15 minutes.
Remove the lid and stir in the shredded chicken, frozen peas, milk and half and half.
Return soup to a simmer (do NOT boil, as this will curdle the broth).
Once heated through, serve soup and top each bowl with biscuit crumbles and fresh chopped parsley.