We would recommend Casa Thomas just outside Costa Teguise, Las Caletas wonderful setting on the edge of the sea. Family run Spanish restaurant. Fantastic for tapas at lunchtime with the waves splashing close by.
We also love La Bohemia which is best for their meats (and if you like a cheeky desert). All the Spanish use it for their steaks.
We have a place in Costa Teguise and visit 4-5 times a year
Jason & Jenny