Not far from San Sebastian, along the coast, the town of Getaria is worth a quick look.
And the bar/restaurant Politena has a good 3 course menu, including bread and wine, for €10.
Not cordon bleu, but more than adequate.
We had our dog with us, so we had to sit outside to eat, but inside looks attractive, with a tapas bar and a restaurant, and it was full on a Wednesday morning in early January - a very good sign.
Definitely worth a try if in the area.