I like to use steel cut oats for swiss oatmeal. Basically, you cook the oats for 8-10 minutes (not supposed to be tender), let cool, then combine with equal parts milk and greek yoghurt (you can add honey and cinnamon at this point). Place in the refrigerator overnight. In the morning, take it out and add whatever toppings you like. I like to add apples, sliced almonds, and dried cranberries.
This is a delicious, very filling cold cereal and a nice alternative to hot oatmeal!