Add 1 ¼ cups of flour to a pie plate and season with seasoned salt, black pepper, garlic powder, and onion powder.

Pour buttermilk into another pie plate and season with a few dashes of hot sauce. Whisk to combine.

Season both sides of the meat with kosher salt, black pepper, onion powder, and garlic powder. Dredge the steaks in the buttermilk, then coat them in the flour mixture.

Pour an inch of oil into a large, deep cast iron skillet and heat over medium-high heat. Fry the steaks in batches in the hot oil until golden brown, about 5 minutes per side. Drain on a paper towel-lined sheet tray and repeat with the remaining steaks.

Carefully drain the hot oil, reserving the cooked bits and 3-4 tablespoons of drippings in the skillet.

Reduce the heat to medium. Sprinkle flour evenly over the drippings and whisk together to form a golden-brown paste. If the mixture is too greasy, add more flour; if it's too clumpy, add more grease. Continue cooking until the roux is a deep golden brown.

Gradually pour in 3 cups of whole milk, whisking constantly. Season with seasoned salt and black pepper to taste. Cook, whisking, until the gravy is smooth and thick, 5 to 10 minutes. Add more milk if the gravy becomes too thick. Adjust seasoning as needed.

Serve the gravy over the chicken fried steak and garnish with green onions if desired.