Hello, Good morning TA!
Just wanted to share that these 2 restaurants, very different style from one another, are open on Sunday
Rias de Galicia, Specializing in Seafood, is more upscale,no prices, but from my research is expensive but if you are looking for a "special sunday" restaurant, this might do the trick
* Located close to the magic fountain- very convenient
L'arros is all about rice dishes, and they do serve "single" paellas & other rice dishes.
* Located in Barceloneta area, close to the metro stop there