Roast pine nuts in a pan without fat and allow to cool. Clean the leek, cut into pieces approx. 2 cm long, rinse and drain well. Wash the raisins and drain them. Heat the butter in a saucepan and fry the leek in it until translucent. Deglaze with broth and pepper. Add the raisins and simmer over a low heat for about 10 minutes, stirring in the breadcrumbs after 5 minutes so that the whole thing is creamy. Season the vegetables with salt, pepper and balsamic vinegar and sprinkle with pine nuts.