Dredge the Chicken: In a shallow dish, mix flour, garlic powder, onion powder, paprika, poultry seasoning, salt, and pepper. Coat the seasoned chicken in the flour mixture, shaking off excess. Save 2 tablespoons of the flour mixture for later.
Fry the Chicken: Heat vegetable oil in a large cast-iron skillet over medium heat. Fry chicken for 4-5 minutes per side, until golden brown (not fully cooked). Remove and set aside.
Make the Roux: In the same skillet, melt butter and sauté onions until soft. Stir in the reserved flour mixture and cook for 1 minute, stirring constantly.
Build the Gravy: Slowly whisk in chicken broth, Worcestershire sauce, and chicken bouillon, ensuring no lumps. Let the mixture simmer until slightly thickened.
Smother the Chicken: Return the smothered chicken to the skillet, covering it with the gravy packet sauce. Cover and simmer on low for 30-35 minutes, turning occasionally, until the chicken is fork-tender.
Finish and Serve: Stir in milk or heavy cream for a richer gravy. Cook for another 5 minutes. Garnish with fresh parsley and serve hot over rice, biscuits, or mashed potatoes.