In a shallow dish, combine ⅓ cup of flour with the salt, pepper, garlic powder, onion powder, and smoked paprika. Dredge each pork chop in the seasoned flour, shaking off excess. Set aside.
Heat the vegetable oil in a large, deep skillet or Dutch oven over medium-high heat. Sear the pork chops for 3 to 4 minutes per side until golden brown. Remove to a plate and set aside.
Reduce the heat to medium. Add the butter to the skillet and let it melt.
Add the sliced onions to the skillet and cook for 8 to 10 minutes, stirring occasionally, until soft and golden brown.
Add the minced garlic and cook for 1 minute, stirring constantly.
Sprinkle the remaining 3 tablespoons of flour over the onions and stir well. Cook for 1 to 2 minutes.
Slowly pour in the chicken broth while stirring to prevent lumps. Add the Worcestershire sauce, dried thyme, and bay leaf. Stir to combine and bring to a simmer.
Return the pork chops to the skillet and spoon onion gravy over each chop. Cover with a lid and reduce heat to low.
Simmer for 35 to 45 minutes, or until the pork reaches an internal temperature of 145°F and the meat is tender.
Remove the bay leaf. Taste the gravy and adjust seasoning if needed. Serve with gravy spooned over the top, garnished with fresh parsley if desired.