You've got some wonderful eating-out advice already.
Now walk around a bit, and when you see some little old lady carrying lots of sacks of groceries try to figure out where she came from. I love grocery stores in any country. Where you will be, you should be able to find wonderful oranges, olives, cheap wine, great bread, unique cheeses and plenty of other things with which to make an inexpensive picnic meal.
In the morning, follow your nose to tiny little bakeries.
It is sort of a treasure hunt. You need to be away from the tourists, and where the locals live.
Sometimes there are grocery stores in the basements of big department stores. And sometimes they are just tiny places with limited hours - early morning for a while, closed for siesta, and then late afternoon for a while.
And then there are the farmer's markets. Wonderful adventure. I found this on a web site - "Thursdays behind Aquapark, from 10.00h to 15.00h". Again, can't vouch for it, but worth a shot.
I can't speak for your destination specifically, but the above techniques has worked for me lots of other places. And you will see lots more of the reality of a country.
Romelle