Heat the oil in a large pan, add the onion and cook over a low heat for about 10 minutes, until soft.
Add the garlic, smoked paprika, tomato puree and carrots and cook for 5 more minutes, stirring often.
Add the butternut squash, potato, tinned tomatoes, bay leaves and stock; bring up to a simmer and cook for about 20 minutes, until the vegetables are almost tender.
Add the farro and lentils and cook for another 15 minutes, until the farro and vegetables are cooked through. Add a splash more stock if needed but the stew should not be too watery.
Meanwhile, cook the sausages according to the instructions on the packet. Once cooked, slice each one into fat pieces.
Season the stew to taste with plenty of salt and pepper, stir through the sliced sausages and serve with crusty buttered bread to soak up the juices.