This is potentially the most varied experience to have in the country.
Portuguese cuisine evolved from hearty peasant food drawn from the seafood of the country's abundant coast and the pork raised on the limited grazing land of its interior. From these humble origins, Mediterranean ingredients and spices brought back to the country during its exploration and colonisation of the East Indies and the Far East helped shape what is regarded as 'typical' Portuguese cuisine.
Soup is the essential first course of any Portuguese meal. The most popular is the Minho specialty, caldo verde, made from kale, potatoes and spiced sausage.
You will see another Portuguese staple bacalhau (dried codfish) everywhere. Locals will tell you that there are as many ways to cook this revered dish as there are days in the year, or even more.
The most common of Portugal's delicious fish (peixe) dishes revolve around sole (linguado) and sardines (sardinha) although salmon (salmão) and trout (truta) are also featured heavily. These are fried, grilled or served in a variety of sauces.
You'll see grills, thick with the smoke of charring meat, in front of many restaurants during your stay. Other than traditional sardines and salmon, Portuguese grilled chicken -- marinated in chilli, garlic and olive oil -- is world famous.
Vegetarians may have a tough time of it in Portugal, at least in traditional Portuguese restaurants. In most restaurants, vegetables (usually boiled or fried potatoes) are simply a garnish to the main meat dish. Even 'vegetarian' salads and dishes may just substitute tuna (which locals don't seem to regard as a 'meat') for ham or sausage. However, the Portuguese really like their choose-5-items salad bars, and restaurants serving Indian, Chinese, Mexican, or Italian fare can be found in most cities.
In many Portuguese restaurants, if you order a salad it will come sprinkled with salt - if you are watching your salt intake, or just don't like this idea, you can ask for it "sem sal" (without salt).
A few restaurants, particularly in non-tourist areas, do not have a menu, you have to go in and ask, and they will list a few items for you to choose from. It is wise to get the price written down when you do this so as to avoid any nasty surprises when the bill comes. However, in this type of restaurants, the price for each one of the options is very similar, varying around from 5 to 10 euro per person.
Most restaurants bring you a selection of snacks at the start of your meal - bread, butter, cheese, olives and other small bites - invariably there is a cover charge on these items, around 5 euro. Do not be afraid to ask how much the cover charge is, and get them to take the items away if it is too much or if you are not planning to eat as much. It can be quite reasonable, but occasionally you will get ripped off.
If you have kitchen facilities, Portuguese grocery stores are surprisingly well-stocked with items such as lentils, veggie burgers, couscous, and inexpensive fruits, vegetables, and cheeses. On larger shops mostly found in the principal cities, you can also find many unusual items such as exotic fruits or drinks.
In some grocery stores the scales are in the produce section, not at the checkout. If you don't weigh your produce and go to the checkout, you will probably be told Tem que os pesar or Tem que pesar ("You have to weigh them").
Snacks
Portugal is famous for its wide variety of amazing pastries, or pasteis. The national pastry, pasteis de nata (called just natas further north), is a flaky pastry with custard filling topped with sugar (acucar) and cinnamon (canela) but, strangely, with a very low caloric content. Buy one (or half a dozen) at the Pasteis de Belem a few minutes by tram from central Lisbon, where supposedly the best pasteis in the country can be found. Also excellent are the bolo de arroz (literally, "rice cake") and the orange-carrot cake.
But don't stop here. Head for Sintra, a short trip away from Lisbon, and try the famous queijadas de sintra. From the more egg-oriented North to almond-ruled South, Portuguese pastry is excellent and often surprising.
On October/November, roasted chestnuts (castanhas) are sold on the streets of cities from vendors sporting fingerless gloves tending their motorcycle driven stoves: a treat!