Jansson’s temptation, a Scandinavian treat

Ingredients 6 medium size red-skinned potatoes, peeled and cut into matchsticks 1 large white onion, peeled and finely sliced 20 anchovy fillets (I used sweet white ones – ideally use Swedish anchovies), chopped 50 g butter 170 ml single cream 200 ml double cream Sea salt and fresh ground black pepper 20 g sourdough breadcrumbs…