Brown the mince: Place a large frying pan or skillet over medium-high heat. Add the beef mince and break it apart with a wooden spoon. Cook for 5-7 minutes, stirring occasionally, until the mince is deeply browned and you hear a satisfying sizzle. The colour should be a rich mahogany, and the fat will have rendered into the pan. Do not stir constantly; let it rest to develop that crust.

Sweat the aromatics: Reduce the heat to medium. Add the diced onion to the pan with the mince and its fat. Cook for 4-5 minutes until the onion becomes translucent and softens, releasing a sweet, fragrant smell. Stir in the minced garlic and cook for a further minute until it becomes aromatic but not browned.

Build the flavour base: Add the tomato purée, smoked paprika, mustard powder (if using), salt, and pepper. Stir everything together and cook for 2 minutes. The purée will darken slightly and stick to the bottom of the pan, creating a deep, concentrated flavour. The smell at this stage should be rich and savoury.

Create the cooking liquid: Pour in the beef stock and whole milk, then add the Worcestershire sauce. Stir well, scraping the bottom of the pan with your wooden spoon to lift any browned bits. Bring the mixture to a gentle boil — you will see small bubbles breaking the surface across the entire pan.

Cook the pasta: Stir in the elbow macaroni, ensuring it is fully submerged in the liquid. Reduce the heat to a simmer and cover the pan with a lid. Cook for 10-12 minutes, stirring once halfway through. The pasta will absorb the liquid and swell; the sauce will thicken and become glossy. Test a piece of pasta — it should be al dente, offering slight resistance when bitten.

Incorporate the cheese: Remove the pan from the heat completely. Add the butter and both grated cheeses, then stir vigorously until everything has melted into a smooth, cohesive sauce. The texture should be thick, velvety, and stretch slightly when you lift the spoon. If the sauce seems too thick, stir in a splash of warm milk.

Rest and finish: Let the pan sit, uncovered, for 3-4 minutes. This rest time allows the sauce to settle and the flavours to meld. During this time, the surface will develop a slight sheen. Just before serving, sprinkle the fresh chives over the top for a bright, clean finish.