In your wok or a large saucepan, soften the onion in the oil without browning it and add the beef, stirring to colour.
Add paprika, chilli powder, tomato sauce and paste and water. Bring to the boil then simmer gently for thirty minutes, adding a little more water if necessary.
Season well with sea salt and ground black pepper to taste.
While the sauce is simmering, cook the sausages over a low heat until just cooked through.
Place a sausage in each bread roll and top with plenty of meat sauce.