In Costa Rica, set meals are called casados. They're wildly popular with ticas (nickname for Costa Ricans) and you find them at casual roadside food stalls; also known as Sodas. Ask locals about the best place in town, the best grub is usually off the main roads for substantially lower prices (and bigger portions!).
Sometimes sodas will be set up buffet style, where you'll most likely find a selection of sweet plantains, patacones (fried, mashed and fried again green plantains), black and red beans or gallo pinto, chuletas (pork chops, usually smoked), stewed chicken and beef, tortillas, cabbage salad, fried yucca and so on. If it's a breakfast casado, eggs will usually replace the animal protein and you might get the option of locals fruits such as mango, papaya, guava or pineapple.
Casados usually run you about $2.25-$5.00, depending where you are. You're gonna be stuffed after one of these puppies.