Preheat the oven to 170°C / 150°C fan / Gas 3.

Season the beef with salt and black pepper. Heat a large casserole dish until very hot, add the oil and 10 g of the butter, then brown the beef in batches. Remove and set aside.

Add the onions and another 10 g of butter to the pan and cook for 2–3 minutes until lightly coloured. Add the carrots and cook for 1 minute.

Stir in the cornflour and cook for 2 minutes. Gradually pour in the red wine, stirring continuously until smooth and slightly thickened.

Return the beef to the pan, add the stock and thyme, season lightly, and bring to the boil.

Arrange the potato slices neatly on top in overlapping layers. Dot with the remaining 5 g butter.

Cover with a lid and cook in the oven for 1 hour.

Remove the lid, increase the oven temperature to 200°C / 180°C fan / Gas 6, and cook uncovered for a further 25–30 minutes until the potatoes are tender and lightly golden.