Wash the herbs. Rub the sage leaves between your fingers to release the aromatic oil and mix together with the olive oil, a little sea salt, a grinding of black pepper and a few needles of rosemary.
Rinse the sausages and pat dry with kitchen paper. Untwist the sausage links and squeeze the meat along the sausage skin so you have one long sausage.
Roll the sausage into a wheel and push in two wooden skewers at right angles to secure its shape.
Bunch together the remaining sprigs and use them as a brush to coat the sausage wheel with the aromatic oil.
Put the sausage wheel on the barbecue and cook for 15 minutes, brushing regularly with the aromatic oil. Flip over and cook for another 15 minutes until browned all over.
Remove the wooden sticks, cut the sausage into chunks and serve.