Mercado del Puerto is worth doing once, at lunch, and it is expensive. The neighbourhood parrilla that locals actually use costs half and serves the same cut.
The chivito is the national sandwich: steak, ham, cheese, bacon, egg and salad. The canadiense has everything; the al plato comes without bread and with chips.
Kitchens close early. Restaurant kitchens in Montevideo usually stop between 3pm and 8pm — plan lunch before 2pm.