Take a chunk of blue cheese, 400 g or more, as needed. Place the cheese in a jar with a hinged lid. Prick the cheese in several places with a skewer to allow the wine to saturate it. Cover the cheese with Port wine. Close the jar and let the cheese soak in the refrigerator or in a cool, dark place. It will be ready in three or four days. Keeps for two or three weeks in the refrigerator. Serve with slices of walnut bread.