Vegetarian Restaurants & Portuguese Desserts

As you may have heard, the Portuguese diet has a lot of meat and fish. On the General Info page of the Festival website:
"Portuguese food is not typically vegetarian, however, there are always vegetarian options available. We are in discussions with local restaurants to ensure that the local restaurants have vegetarian options available. For those with a sweet tooth, Portugal’s pastries are legendary as is the coffee which is very short and very strong!"

LuckyCow Cascais Vegetarian & Vegan Restaurants, which I've referred to for a few trips in Europe, as they have wide coverage
TripAdvisor List of Cascais Vegetarian & Vegan Restaurants - note the filters in the left sidebar for various cuisines, price, etc.

Lisbon Vegetarian Restaurants on LuckyCow
Lisbon Vegtarian Restaurants on GoLisbon
Lisbon Vegetarian Restaurants on TripAdvisor

For dessert, take a look at this interesting article with photos: Sweet, sweet Portuguese cakes and desserts. That writer also has a separate page for the most famous Portuguese dessert, patel de nata, which says in part: "Many of Portugal’s best cakes were originally baked by monks and nuns, and the original recipe for pastéis de nata came from the monks at the Jerónimos Monastery in Belem, Lisbon. These days, people queue outside the most famous specialist bakery Casa Pastéis de Belém in Lisbon which began producing these cakes using the monks’ secret recipe after Portugal’s monasteries and convents were closed down in the 19th century."