If you google "7 minute cooked frosting" you'd probably get the recipe.
I'm sorry I'm replying this from my phone, and it's not possible to open more than one window to copy and paste the recipe for you, but from the top of my head, if I'm not mistaken the recipe involves you cooking 5tbsp of flour in a cup of milk, cool it, covered, to avoid skin forming on top of the mixture.
Then whip a cup of butter till fluffy and add the cooled flour + milk mixture into it and whip more.
Hmm now where and when do I add the sugar???? Ha ha I'm soooo unreliable.
Sorry if I'm of no help to you.