Staple Foods
There are a number of common ingredients in Portuguese cooking, including olive oil, pork, meats/fish, and pastries, but the country only has one true staple food:
Bread: always on the table with meals, a simple, but necessary start to any meal
Regional Variations & Specialties
Arroz de Marisco: rice, shellfish, and fish stew
Bacalhau: the national dish, dried and salted cod
Cozido a Portuguesa: vegetable and meat (usually pork) stew
Tripas a la Porto: stomach (generally beef stomach) and bean stew with fish
Dining Etiquette
Pastel de nata
Once the meal arrives there are no unusual formalities to dining in Portugal, however prior to this point, greetings and dress must be addressed. Dress conservatively, but well and be sure you have the right shoes as every Portuguese is sure to take a glance at them. When you arrive (about 15 minutes late is appropriate), shake everyone's hand and make eye contact. If you're eating in a local's home, be sure to also bring a gift such as candy or chocolates.
Once the host invites you to sit down, sit when everyone else does and don't begin eating until the host indicates you can with the words "bom appetito." Leave your napkin on the table and use it to dab your mouth if needed; also be sure to eat in the continental style (knife in the right hand, fork in the left). If in a home, the food will most likely be served family style, let the guest of honor serve him or herself first.
As you finish eating, move your napkin from the left side, to the right side of your plate and leave a little food on your plate. If dining out the host will most likely pay for everyone present and men will generally not allow women to pay. If you are paying the bill, get the server's attention by making eye contact, but don't wave as that can be considered rude.