Preheat the oven to 170C/325F/Gas 3.
Season the meat with salt and freshly ground black pepper.
Heat a large casserole dish until very hot then add the oil and a small knob of butter. Fry the beef until browned all over, then remove from the pan and set aside. (You may need to do this in batches.)
Add the onions and another knob of butter to the pan and fry for 2-3 minutes, or until lightly browned. Add the carrots and cook for a further minute.
Stir in the flour then gradually add the red wine, stirring until smooth. Add the browned beef and the stock, season with salt and freshly ground black pepper and bring to the boil. Stir in the fresh thyme, then arrange the potatoes on top. Dot the surface with the remaining butter.
Cover with a lid and cook in the oven for one hour.
Remove the lid and increase the heat to 200C/400F/Gas 6 for 30 minutes.