February 2026 · 4 min read
Portuguese food is celebrated for its simplicity and quality of ingredients. But some classic dishes carry allergen risks that are easy to overlook — especially if you are relying on a menu description alone.
The most common surprise for gluten-free diners is the widespread use of breadcrumbs and flour as thickeners. Açorda, migas, and many traditional sauces start with stale bread. Fish and meat dishes are frequently dusted with flour before pan-frying — even if the menu describes them simply as "grilled" or "pan-fried." Shared fryers are also common in casual restaurants: even if your dish is naturally gluten-free, it may be cooked in oil that has been used for battered items.
Butter is the default cooking fat in a large number of Lisbon restaurants, including many that describe their cuisine as "light" or "Mediterranean." Sauces, rice dishes, and vegetables are often finished with butter without this being mentioned on the menu. If you are dairy-free, always ask whether dishes are cooked in butter or olive oil — and whether cheese is used as a garnish or mixed into dishes.
In seafood-heavy Lisbon, shellfish stock (often made from prawn heads and shells) is used as a base for rice dishes, fish stews, and sauces. If you have a shellfish allergy, dishes that appear fish-only may still carry a risk. Arroz de marisco (seafood rice) is an obvious one, but bisques, cataplanas, and even some soups may contain shellfish-derived stock.
Portuguese desserts are exceptionally egg-heavy — this is a legacy of the country's convent pastry tradition, which used surplus egg yolks (the whites were used to starch nuns' habits). Almost every traditional pastry — pastéis de nata, toucinho do céu, ovos moles — contains significant quantities of egg. If you are egg-free, dessert menus in traditional restaurants will typically offer very limited options. Modern restaurants and cafes are a safer bet.