Preheat the oven to 190°C/375°F/gas mark 5.

Prick the potatoes all over with a fork, then rub with a little oil. Set them on a bed of rock salt in a tray and bake for 1–1½ hours, or until tender.

Heat a large sauté pan until hot. Add the vegetable oil and fry the beef until just browned. Add the onions, garlic, thyme and celery, and fry for a couple of minutes until softened. Add the tomato purée and cook for 1–2 minutes, then add the Worcestershire sauce and one of the carrots, finely diced. Add the red wine and cook until reduced by one-third, then add the beef stock and bring to a simmer, stirring occasionally. Cook for 30 minutes until the beef is tender and the sauce has thickened.

Tip the mince into a bowl and season to taste with salt and pepper, and as much Worcestershire sauce as you like. Set aside in the fridge to cool while you make the mash.

While the beef cools, top and tail the remaining carrots and place them in a pan half-filled with water. Add a pinch of salt, the sugar and a knob of butter, bring to the boil, then reduce to a gentle simmer and cook for 30–40 minutes until soft. The liquid should evaporate, leaving a lovely glaze to the carrots.

When the potatoes are cooked and just cool enough to handle, slice them in half, scoop out the flesh and pass through a potato ricer into a bowl. Turn the oven up to 220°C/425°F/gas mark 7. Add almost all the remaining butter to the potatoes and warm the milk in a saucepan until just simmering. Pour onto the potatoes and beat until the mash is smooth and creamy. Season to taste with salt and pepper.

Pour the cooled mince into a baking dish and spoon the hot mash over the top, fluffing the top with a fork. Scatter over a few dots of butter, then place in the oven for 10–15 minutes, until golden-brown and piping hot throughout. Serve with the carrots.