The manager of my hotel, Villa Albero, pointed this place out on the map she gave me. I went down and had jamon on toast and a nice cool white wine for 3€. The jamon was good quality and very tasty. The wine was nice. Refreshing.
After that I visited several times.
They do a hot chocolate and sugared churros (long donuts) for 2€.
The menu is in several languages and it explains that you order and they'll shout your name or to collect it.
Excellent place to sit and soak up the sun or to shelter from the wind after a nice long walk. Friendly and polite staff.