Season the pork chops. Pat the pork chops dry with paper towels. Season both sides with salt, garlic powder, onion powder, smoked paprika, and black pepper.
Coat with flour. Place 1/3 cup of the flour in a shallow dish. Lightly coat each pork chop in flour, shaking off any excess. Reserve the remaining flour for the gravy.
Sear the pork chops. Heat the vegetable oil in a large skillet over medium-high heat. Add the pork chops and sear for about 3–4 minutes per side, until golden brown. Transfer them to a plate.
Cook the onions. Reduce the heat to medium and add the butter. Add the sliced onion and cook for 6–8 minutes, stirring occasionally, until softened and lightly golden.
Add the garlic and flour. Stir in the minced garlic and cook for about 30 seconds. Sprinkle in the remaining flour and cook for 1 minute, stirring constantly.
Make the gravy. Slowly pour in the chicken broth while whisking or stirring continuously. Scrape up the browned bits from the bottom of the skillet. Stir in the heavy cream and thyme.
Return the pork chops. Place the pork chops back into the skillet along with any juices from the plate. Spoon some of the onion gravy over the chops.
Simmer gently. Reduce the heat to low, cover, and simmer until the pork chops are tender and reach an internal temperature of 145°F. Depending on their thickness, this will usually take about 10–15 minutes.
Finish and serve. Taste the gravy and adjust the salt and pepper as needed. Let the pork rest briefly, then garnish with chopped parsley and serve warm with plenty of onion gravy.