I was curious and some quick research suggests the following:
Tyranids are almost certainly inedible if not outright poisonous. They are biological machines and may have features such as acidic blood, ingestion-based mutagens, etc
On the other hand, Orks may be tasty, they’re mushroom based and anecdotally better than guard rations. Kind of like a slightly less ethical Impossible burger
I was curious and some quick research suggests the following:
Pretty sure Ork burgers either end with spreading the Ork fungus to other planets or a slightly too rare burger growing grots inside your intestines