This cozy dish takes its cue from pastelón, a Puerto Rican casserole that varies by region but usually includes plantains, meat, onion, bell pepper, cheese, tomato, olives, herbs, spices and sometimes raisins. Traditionally, the meat mixture and the plantains are layered, which is why some call it "Puerto Rican lasagna." Here, we use the plantains as a top crust, in the style of shepherd's pie.
Season a medium pot of water with the salt and bring to a boil over high heat. Add the plantains and simmer until tender, about 15 minutes. Transfer the plantains to a bowl and mash with the 3 tablespoons butter until smooth. Set the mixture aside.2.
Preheat your oven to 400 F. Butter a medium baking dish; set aside.3.
Heat the olive oil in a large skillet over medium-high heat. Add the beef and adobo seasoning and cook, breaking up with a wooden spoon, until it's browned. Remove beef from the pan and transfer to a bowl. Reduce heat to medium and add the onion, pepper, cumin, paprika and oregano; cook, stirring, until translucent, about 6 minutes. Return beef to skillet. Add the tomato sauce, olives and capers and simmer, stirring occasionally, until the liquid evaporates. Remove from heat.4.
To assemble the casserole, spread the meat mixture in the bottom of the baking dish. Pour the eggs over the meat mixture, then spread the plantains over that. Top with the cheese. Bake, uncovered, until the cheese is golden-brown, 30 to 40 minutes. Serve warm.