Haven't made this, but it sounds good! The recipe calls for 6 fresh corn cobs, so I looked up the conversion charts, which suggests that 1 medium corn cob yields about 3/4 cup of corn. That would be 4.5 cups of frozen or canned corn, which sounds like rather a lot, to 200 gr of potatoes, which is about one large potato. Although the corn is pureed, which would make a difference. So I'm going to suggest 3 cups corn, but if you feel that this is too much, or too little, adjust accordingly. And let us know! :D
Recipe comes from "Gourmet Stews And Mash".