This is one of the most local and authentic meals you can have in Lisbon. This lovely place is run by nuns serving decent but quite basic food.
It’s a bit hard to find: once you get to the address there’s no indication but enter the building and go upstairs, the restaurant is located on the last flore of building.
If you are lucky you can try to get a table on the terrace where there’s an astonishing view! Otherwise just get a seat wherever you find you one.