Why go
Use the region to guide what you order. Paella is associated with Valencia; gazpacho and salmorejo point toward Andalusia; Galicia is noted for fresh produce and seafood. Tortilla de patata, legumes, cured meats and cheeses appear more broadly, often with local variations worth comparing.
The full story
Olive oil, garlic, onion and sofrito, a cooked flavour base, recur in many Spanish dishes. They do not make the country's kitchens uniform. Rice dishes are closely linked with Valencia, while Andalusia offers gazpacho and the thicker salmorejo, along with fried fish and cured ham. Galicia's cooking draws on fresh local ingredients. Legume stews, bread, cheeses and cured meats also change from region to region. Familiar sweets include flan, arroz con leche and churros. The old tendency to describe paella as a fixed mix of seafood, chicken and chorizo misses that regional range; its Valencian origin is a better starting point for understanding the dish. For a food-led journey, compare a few characteristic dishes in their own regions instead of looking for one menu that claims to represent all of Spain.