Unfortunately you live in Germany. Are there any local immigrant groups where you live that comes from an island/coastal culture? These have been a big resource for me, in terms of local markets where I can buy their foods, get advice, and learn how to cook it. A big obstacle I think for starchy diets is having trouble getting enough calories and then feeling irritable, learning how to cook some of these things right can help make them much more appetizing. For example, I learned quite a bit from local people from Puerto Rico, Thailand, Malaysia, and the Ivory Coast when I lived in Queens. Some of these starches are also traditionally fermented and/or pounded, which can affect digestion substantially.

Otherwise, checking out cookbooks and blogs is a good start and planning them out using nutrition software like Cron O Meter.

One thing I would be aware of is that peoples adapted to heavy starch diets often have polymorphisms related to folate metabolism that allow them to need less folate. If you are German, I doubt you have that and you'll need to eat more leafy greens or other sources of folate.

Are you Kitavan? Might not work out so well for you if you're not of that genetic line. Don't think anyone knows for sure. They know that Kitavan's can get fat eating Western food (much like many of the Pacific Islanders). Don't think they've shown that Westerners can get thin eating Kitavan food.

Check out: http://wholehealthsource.blogspot.com/2008/08/kitavans-wisdom-from-pacific-islands.html and http://wholehealthsource.blogspot.com/2010/12/interview-with-kitavan.html