Never heard of Casey's, but I'm suddenly a huge fan of a giant biscuit smothered in rich sausage gravy as a serving suggestion.I'm a fan of Casey's breakfast pizza. I get it with the sausage gravy "sauce" (cheese sauce is an option too) with sausage, bacon, ham, extra scrambled eggs and cheese.
Gravy with plenty of sausage and a few chunks about the size of your thumb left in for style.