Prepare the Chicken: Place a chicken breast between two sheets of cling film or baking parchment. Using a meat mallet or a rolling pin, gently pound the chicken until it is an even thickness of about 1.5cm (just over ½ inch). This ensures it cooks evenly. Repeat with the remaining chicken breasts.

Set Up the Dredging Station: You'll need two shallow dishes. In the first, whisk together the 250g plain flour, salt, 2 tsp black pepper, paprika, garlic powder, onion powder, and mustard powder. In the second dish, whisk the eggs and milk (or buttermilk) together until smooth.

Double Dredge the Chicken: Take one pounded chicken breast and dredge it thoroughly in the seasoned flour, shaking off any excess. Next, dip it into the egg wash, ensuring it's fully coated. Finally, place it back into the seasoned flour for a second, generous coating. Press the flour onto the chicken firmly to help it adhere. Place the coated chicken on a wire rack. Repeat for all pieces.

Rest the Chicken: Let the coated chicken rest on the wire rack for at least 10 minutes. What works best for me is using this time to get my side dishes ready. This resting step is vital; it allows the coating to hydrate and cling to the chicken, which prevents it from falling off during frying.

Fry the Chicken: Pour the oil into a large, heavy-bottomed frying pan or skillet to a depth of about 2cm. Heat over a medium-high heat until it reaches 175°C (350°F). If you don't have a thermometer, a pinch of flour should sizzle vigorously when dropped in. Carefully place two pieces of chicken in the pan, ensuring not to overcrowd it. Fry for 4-5 minutes per side, until deep golden brown, crispy, and cooked through. The internal temperature should be 74°C. Check government advice like from the Food Standards Agency (FSA) for the latest safe cooking temperatures.

Drain and Keep Warm: Remove the cooked chicken from the pan and place it back on the wire rack to drain. You can keep the cooked chicken warm in a low oven (around 100°C) while you fry the remaining batch.

Make the Pan Gravy: Carefully pour off all but about 60g (roughly 4 tablespoons) of the hot oil from the pan, leaving the browned, crispy bits (the fond) behind. Return the pan to a medium heat. Whisk in the 60g of flour to create a paste (a roux). Cook for one minute, stirring constantly.

Finish the Gravy: Gradually pour in the whole milk while whisking continuously to prevent lumps. Bring the gravy to a simmer and cook for 3-5 minutes, until it has thickened enough to coat the back of a spoon. Season generously with the remaining 1 tsp of black pepper and salt to your taste.

Serve Immediately: Serve the crispy chicken fried chicken immediately, with a generous ladle of the creamy pepper gravy poured over the top.