Firstly, this is porridge. You call it oatmeal, which to be fair is a better name for it because it's a meal of oats.
Sometimes, porridge is served as a sort of starter before the breakfast main course. The breakfast main course is called a "full Scottish," and contains the most important food groups: namely carbs, meats, and crunchy bits.
Sometimes, the meat group is represented by haggis, a sort of sexually suggestive pudding made with ground animal organs, (misc.), oats, (???), and spices.
Incidentally, this is the best food you'll ever eat. It is a sausage, but it's vastly different to what you call a sausage, because it is square. The squareness makes it taste better.
We sometimes put haggis inside square sausage, but this is a complex issue and, trust us, you're not ready for it.
We also put square sausages inside rolls. We call this a "roll and sausage", because we are a literal people.
We also serve other foods inside bread rolls, mainly pies. But not fruit pies, that would be crazy! Can you imagine? Ha ha! No, we put macaroni cheese pies inside bread rolls.
This is far more sensible.