Prepare the masa by mixing masa harina with warm water, melted butter, and salt until smooth. Add sour orange juice (or substitute with lime juice) and mix thoroughly. Set aside to rest for 30 minutes.

Season the pork pieces with salt, black pepper, cumin, oregano, and minced garlic. Let marinate for 20 minutes.

In a large bowl, combine partially cooked rice with diced potatoes, bell peppers, onions, and tomatoes. Season with salt and pepper.

Prepare banana leaves by briefly passing them over an open flame to make them pliable, then cut into 12-inch squares.

To assemble each nacatamal, place a banana leaf square shiny side down. Spread a generous portion of masa in the center, creating a rectangle about 6x8 inches.

Layer the filling: place 2-3 pieces of marinated pork in the center, add a spoonful of the rice-vegetable mixture, top with a few olives, raisins, and a sprig of cilantro.

Fold the banana leaf over the filling, first the sides, then the top and bottom, creating a secure rectangular package. Tie with kitchen twine.

In a large stockpot, arrange nacatamales standing upright. Add water to reach halfway up the packages. Bring to a boil, then reduce heat to maintain a gentle simmer.

Cover and steam for 2.5 hours, checking occasionally to ensure water level remains adequate. Add more hot water if needed.

Remove from pot and let rest for 10 minutes before serving. Unwrap carefully and serve hot with the banana leaf as a plate.