Adega Sao Nicolau in Porto's Ribeira has been pouring red since the 1940s, serving polvo a lagareiro on a small Douro-facing terrace below the quay.
Signature dishes: Polvo a lagareiro, Bacalhau a Gomes de Sa
Must order: Polvo a lagareiro: octopus baked with potatoes, garlic and a slug of olive oil.
Tip: Lunch service from noon. The river-side terrace fills first; the inside room is cooler in August.
Address: Rua de Sao Nicolau 1, 4050-561 Porto
Cafeina in Foz do Douro, Porto, occupies a tiled corner villa where the kitchen pairs Portuguese classics with international turns and a serious wine cellar.
Signature: Bacalhau a la Cafeina, Tournedos with foie
Order: Bacalhau a la Cafeina, then the chocolate cake in port-wine reduction.
Tip: Closed Mondays; lunch and dinner Tuesday to Sunday. The walled garden books out on Saturdays.
Flow in Porto's Baixa pairs a sushi counter with a Mediterranean kitchen across two floors and a roof terrace, on a quiet Conceicao side-street near Cordoaria.
Signature: Tuna tartare, Black-rice seafood
Order: The tuna tartare to start, the black-rice seafood to follow.
Tip: Walk up to the roof bar for a Touriga Nacional flight after dinner.
MUU Steakhouse on Rua do Almada in Porto serves dry-aged Portuguese and international cuts from a glass maturation room, with a kilo-cut to share.
Signature: Maturated tomahawk, Iberian secreto
Order: The maturated tomahawk to share, with the smoked-potato gratin.
Tip: Dinner only, 18:00 to midnight. Bring an appetite; portions are sized for two.
Brasao Aliados in Porto opened in 2014 as the first Brasao Cervejaria, with the city's most-Instagrammed francesinha and a black-garlic mayo for rissoles.
Signature: Francesinha, Meat rissoles with mushrooms
Order: Francesinha with the egg on top, croquette flight to share.
Tip: Open daily. Queues from 12:30 to 14:00; book ahead or arrive at noon.
Cafe Santiago on Rua de Passos Manuel in Porto is the most-cited francesinha counter, layered with mortadella, sausage and steak under tomato-beer sauce.
Signature: Francesinha
Order: Francesinha especial with egg, side of fries to soak the sauce.
Tip: Closed Sundays. The original 226 site is the one locals defend; the second site up the street is overflow.
Bufete Fase on Rua de Santa Catarina in Porto is the locals' francesinha counter, an even-keeled sauce balanced by the same owner since the 1990s.
Signature: Francesinha
Order: Standard francesinha. No egg, no fries, just bread and sauce.
Tip: Cash only. Queue starts at 12:30; arrive earlier and you might get one of the eight tables.
