Now, pay attention........
Basically, we could divide what has impacted on spanish food into three reasons.
I quote from "Enforex", the website.
Geography of Spanish Food
The basis of the history of Spanish food of course has to do with its geographical situation. First of all, the country is located on the Iberian peninsula and is almost entirely surrounded by the waters. Naturally, due to this fortunate location, seafood forms one of the pillars of Spain's gastronomy and categorizes the country as having a Mediterranean diet. The rest of Spain is a diverse terrain made up of mountain ranges, lush pastures, fertile farmgrounds, extensive coastlines and more, which together provide quite the variety of fresh products. For example, Spain's famous hams are cured high in the mountains, vineyards and olive groves sprawl across expanses of land, and fresh fruits and vegetables hail from throughout the country..(http://www.enforex.com/culture/history-spanish-food.htmlCultures Throughout the History of Spanish Food
Endless cultures, as they passed through or settled in Spain, have influenced the history of Spanish food. The Phoenicians left their sauces, the Greeks introduced Spain to the wonders of olive oil, and Romans, Carthaginians, and Jews integrated elements of their own cooking into that of Spain. However it was the Moors who, during their centuries of reign, most impacted Spanish gastronomy. They introduced fruits and light seasonings into the Iberian diet, as well as combinations of fruits and nuts with meats and fish. Rice- a genuine staple of Spanish gastronomy- and therefore Spain's vast array of rice dishes, come straight from the Moors, as does the use of saffron, cinnamon, and nutmeg. As you eat gazpacho on a hot summer day, thank this clearly gastronomically talented Moorish culture, as it too comes straight from them. Conclusion? Ironically enough, the foods we consider to be "typically Spanish" would either not exist or would be extremely different without the intervention of so many cultures into the history of Spanish food..(http://www.enforex.com/culture/history-spanish-food.htmlThe Americas' Impact on the History of Spanish Food
Along with its obvious historical impact, the discovery of the Americas with Christopher Columbus' famous 1492 voyage resulted in the addition of more important elements to the history of Spanish food. As of 1520, foods from the new lands arrived in Spain and immediately began to integrate themselves into the Spanish diet. Amongst the many products that crossed the Atlantic and arrived on Spanish turf, tomatoes, vanilla, chocolate, various beans, and potatoes - which surprisingly arrived in Spain before arriving in Ireland- are all staples of today's Spanish kitchen.(http://www.enforex.com/culture/history-spanish-food.html)So, you see? because of the geographical, cultural and American's impact, here comes spanish food.