I think I say the recipe of diet Unicorn on my Recipe Book of a Summoning Master. Let me take a look...
Oh, it seems like you only need to add some things to the original recipe and take out the virgin bloods. The list is :
Shredded cheese of three kind.
Raspberry
Strawberry
Cherry
Fungi. You could find em on the side of the Dark Poisonous Pond.
Crows Blood.
A tiny pieces of your own liver.
The process is the same as the normal Unicorn.
Happy Hunting!