If you like hearty, mountain fare as I do, Restaurante Serra da Estrela is an extremely useful restaurant to know about when one is in Lisbon. At first blush, it doesn't seem like my kind of restaurant: it's a chain (albeit a small one), all the locations are in shopping centers (centros comerciais), and it's a touch on the expensive side, though not ridiculous by any means. But the food is good... better than good, and they're open when other restaurants are not. Sometimes you just need a meal outside of normal meal times, and that can be tricky in Portugal!
The food is the real deal--not like O Albertino (what is?), but very good. They use authentic enchidos (the general word for cured meat products like chouriço, morcela, etc.)--very important, since at least one variety figures into almost every dish of the region. The sopa do cantinho, a hearty bean and vegetable soup with a couple of cured pork products (naturally) is a satisfying starter, as is the chouriço stewed in red wine. Having eaten here countless times over the years, some of the memorable main courses I've had include açorda de entrecosto (a kind of thick, moistened-bread stew with pork spareribs), chanfana de borrego (lamb stewed in red wine), rancho à moda da Beira (a hearty stew of chickpeas, macaroni, chouriço, morcela, bacon, and farinheira, a type of sausage made with bread, paprika and garlic), galinha de cabidela (possibly my favorite dish in Portuguese cuisine: chicken stewed with giblets, then rice cooked in the resulting giblet broth, with chicken blood added at the end), and alheira de caça (a fried thick sausage filled with shredded pheasant and partridge meat, bread, and garlic).
And, perhaps best of all, they can always be counted on to have good queijo da serra on hand. Queijo da serra is, for me, one of THE great cheeses of the world--runny ambrosia on a plate. And, at around €4 a serving, a relative bargain.
Restaurante Serra da Estrela - Cantinho Regional
Amoreiras Shopping Center, Atrium Saldanha,
Centro Colombo, Centro Vasco da Gama,
CascaiShopping (Alcabideche - Cascais),
and other centros comerciais around Portugal