Heat a splash of oil in a large pot and brown the meat well on all sides. Season with salt and freshly ground pepper.
Add the butter and let it melt, then fry the onion, garlic and pepper until the onion is soft and translucent.
Add the paprika and tomato purée and let them cook for a couple of minutes, then sprinkle over the flour and stir to combine.
Add the stock and bay leaf, cover and leave to simmer for about 1 1/2 hours.
Add the carrots and simmer for a further 30 minutes - or until the carrots and meat are tender.Meanwhile, make the mashed potatoes.
Season the sauce to taste with salt and freshly ground pepper - and a splash of red wine vinegar if you like - and sprinkle with parsley.
Mashed potatoes
Boil the potatoes in plenty of unsalted water until tender, about 20-30 minutes depending on size.
Drain, reserving a little of the cooking water to adjust the consistency.
Mash the potatoes with a potato masher, add the butter and crème fraîche and beat the mash well with a whisk. Adjust the consistency with the reserved cooking water and season to taste with salt.You can also mash the potatoes with a whisk for a coarser texture, or use a hand mixer for a smooth mash. Be aware that the mash can turn "gluey" and stretchy when you use a hand mixer - depending on the type of potato and its starch content.
Serve the goulash with the mashed potatoes and fresh parsley on top.