When it comes to Spanish cuisine and vegetarians the two don’t exactly mix, although there is an increasing number of restaurants opening up in the bigger cities (Madrid and Barcelona) who are catering for vegetarians. Outside of the cities, you can usually find something to eat, but it will be usually egg based and you will quickly get bored of. However many tapas restaurants, more so in the south, are vegetable based (for example fried aubergine or spinach and chickpeas), while fresh fruit, veg and superb cheese is always available in markets and shops.
When it comes to going to restaurants you are faced with an extra problem because the Spanish don’t regard ham as real meat so often that and tuna are added to vegetable dishes and salads; you’ll also find chunks of chorizo turning up in otherwise veg-friendly soups or bean stews. The phrases to get to know are Soy vegetariano/a. Como sólo verduras. Hay algo sin carne? (“I’m a vegetarian. I only eat vegetables. Is there anything without meat?”); you may have to add y sin marisco (“and without seafood”) and y sin jamón (“and without ham”) to be really safe.
Some salads and vegetable dishes are strictly vegan, but they’re few and far between. Fruit and nuts are widely available, nuts being sold by street vendors everywhere.