Why is the food in southern Portugal food so much tastier than the food in southern Spain?

That happens from north to south, all along the border, portuguese restaurants, especially on weekends, are always full of spanish. The spanish might have good "snacks", tapas, but when it comes to real dishes the portuguese beat the spanish in every possible way.

I don't agree with you. I live in Andalusia in Spain. One reason I don't go too often is because Portugal is much more expensive than Spain. Both countries have great dishes. The most popular Portuguese dish is the cataplana. Cataplana originated in Mozambique and not Portugal, Though I do have a cataplana and love to cook the Portuguese way. I live in a rural Andalucian village. The food here is tremendous, the quality and the variety, but the overriding reason I don't go to Portugal is the price and Andalucia is a more beautiful place to live. If you are a tourist to Portugal you will love the place, but living so close I find Spain much more exquisite in both food and culture, but then that is only a personal opinion. I'm sure the real Portugal away from the coast will have a lot more to offer.

I like Portugal and appreciate the food of Portugal, but you cannot compare with spanish gastronomy, possible the best in the world. And in Spain, I think the best is in the north. But in Andalucia, for example the quality of gastronomy is great. In any part of Spain, the quality is exceptional. For other hand, I like portuguesse gastronomy although I think is not very developed.

Well, to each their own I guess.