Cuba is the largest island in the Caribbean, and with that size comes more regional variety than outsiders realize. In particular, the Oriente region of Cuba, facing Haiti and closer to the equator than the rest of this already-tropical island, are known for spicier fare than parts farther north. Bayamo, one of the oldest cities in Cuba, is at the heart of this region, and gives its name to this curious casserole.
Tortilla de papa is usually known as “Spanish omelette” in English, and is a staple of Cuban and Cuban-American breakfasts, sandwiches, and more. Understanding what I just wrote there requires a little etymology lesson.