My favorite soda near my school is named Soda de Mary and is run by an Argentinian woman named Mary. This soda has a few tables and the small kitchen takes up about half of the space. You can watch as Mary prepares the dish. Most of the food is prepared ahead of time, but I always see her cooking a big pot of beans on the stove with plenty of spices.
Because the casado plate has many components and different styles of preparation, one can customize the casado to your liking when ordering. Building the plate starts with plain white rice, beans (typically black beans cooked with plenty of spices and peppers and onions) and steamed vegetables. Then, the customer has a choice of meat (like chicken, beef or pork), fish or vegetarian (with eggs and/or fried cheese). Most of the casados that I've had are served with a green salad with vinegar and oil, but I have also seen them served with potato salad. The best part of the dish is the platanos marudos (ripe plantains) which are like caramelized plantains and add sweetness to the dish.
The dish originated when San Jose became a hot spot for the workforce and many people (mostly men) were seeking home-cooked meals. The servings are also large in comparison to other dishes, as it is meant to replicate a plate served in a typical Costa Rican home.
The name "casado" means "married" or "married man," thus paying homage to the historical role of a married woman in the kitchen.