In a large skillet, melt 1/2 cup of butter over medium-high heat. Place the flour, salt and pepper into a medium bowl and mix until combined. Dredge the chicken in the mixture and then place in the skillet.
Cook the chicken, turning over as needed, until it is brown on all sides.
Remove from skillet and set aside.
Empty the skillet, leaving about 1 tbsp of butter drippings remaining.
Heat the skillet to medium-low, then add in onions, celery, carrots, and mushrooms.
Saute for 15 minutes or until the vegetables are tender.
Add in the flour, stirring to coat the vegetables and cook for 5 additional minutes, then add in the chicken broth.
Stir in the poultry seasoning, and add salt and pepper to taste. If desired, add more poultry seasoning to taste.
Bring to a low simmer and reduce the heat to low.
Place chicken back in the skillet, cover with a lid and continue cooking for 20-30 minutes or until chicken reaches a temperature of 165 °F and the gravy has thickened. Stir the sauce occasionally and turn the chicken once while cooking.,
Spoon over rice or pasta and serve.
Notes
Feel free to add vegetables of your choice to this.