On the Convega site there are descriptions of typical dishes served in the Vega Baja.
Here is one which we have found in many restaurants including the one at IKEA.
Cocido con Pelotas
Meatballs made with turkey blood and meat, egg, parsley, garlic and pine nuts cooked slowly with potatoes, chick-peas, vegetables all seasoned with saffron and salt.
Be warned though it is very filling. You won't want more than a plateful.