Preheat the oven to 220°C (200°C fan). Line a baking tray with parchment paper. In a large mixing bowl, whisk together 450g plain flour, 2 tablespoons baking powder, 1 teaspoon salt, and 1 teaspoon sugar. The mixture should look uniform and feel fine and powdery between your fingers.

Cut in the cold butter. Add the cold butter cubes to the flour mixture. Using a pastry cutter or your fingertips, work the butter into the flour until it resembles coarse breadcrumbs with some pea-sized butter lumps remaining. You should see distinct yellow flecks throughout—this is the key to flaky layers.

Add the milk and bring together. Make a well in the centre and pour in 300ml cold milk. Stir with a fork just until a shaggy dough forms—it will look uneven and rough. Turn it out onto a lightly floured surface and gently knead 4–5 times until it just holds together. Overworking it will make the biscuits tough.

Pat and cut the biscuits. Pat the dough into a rectangle about 2.5cm thick. Fold it in half, then pat out again to 2.5cm thickness—this creates extra layers. Using a floured 7cm round cutter, press straight down without twisting (twisting seals the edges). Place biscuits 2.5cm apart on the prepared tray. Brush tops with melted butter. Bake for 14–16 minutes until deep golden brown and fragrant. The biscuits should sound hollow when tapped on the bottom.

Start the gravy base while biscuits bake. Heat 1 tablespoon olive oil in a large frying pan over medium-high heat. Add the minced beef and cook, breaking it apart with a wooden spoon, until deeply browned—about 6–8 minutes. You'll hear a vigorous sizzle that quiets as the moisture evaporates. The meat should smell nutty and look caramelised in spots.

Sweat the aromatics. Reduce heat to medium. Add the diced onion and cook for 3–4 minutes until softened and translucent. The onion will release moisture and the pan will steam slightly. Stir in the minced garlic, 1 teaspoon black pepper, and smoked paprika if using. Cook for 30 seconds until the garlic smells fragrant but not burnt.

Make the roux and finish the gravy. Sprinkle 3 tablespoons plain flour over the meat mixture and stir constantly for 1 minute—the paste will look dry and smell toasted. Slowly pour in 700ml milk while whisking continuously to prevent lumps. Increase heat to medium-high and bring to a gentle simmer, stirring often. The gravy will thicken after 4–5 minutes; it should coat the back of a spoon and have a smooth, glossy sheen. Stir in Worcestershire sauce and season with salt to taste. The final gravy should be thick enough to hold a line drawn through it with the spoon.

Assemble and serve. Split each warm biscuit in half and place the bottom halves on plates. Spoon a generous amount of gravy over each bottom half, then cap with the biscuit top. Spoon additional gravy over the top, letting it cascade down the sides. Finish with a final crack of black pepper and a sprinkle of fresh parsley. The biscuits should yield a crisp exterior with a soft, steamy interior when broken.