I'd make custard with the yolks.
Why aren't you eating the yolks? The yolks are the tastiest part of the egg! Plus the yolks are where all the vitamins and minerals are.
Check out the difference in vitamin and mineral content between just the whites. nutritiondata.self.com/facts/dairy-and-egg
And the whole egg. nutritiondata.self.com/facts/dairy-and-egg
No question about it the whole egg is so much better for you.