Preheat the grill to medium. Slit and remove the skins from the sausages. Put a frying pan over a medium heat on the hob and add the sausages with a good pinch of dried chilli flakes. Roughly break up the meat and cook the sausages until well browned and tender.
Place the naan breads on a baking sheet and top with the browned sausagemeat and the crème fraîche. Scatter over the red onion and some fresh mint leaves, roughly chopped. Grill for 3-4 minutes.
Remove from the grill and top each naan with a handful of rocket leaves and a drizzle of olive oil before serving.