Hi Mike. If I know my Arenal from my elbow, your parents' place is very close to Benalmadena Pueblo, above Arroyo de la Miel. Nothing immediately on your doorstep, although the Pueblo can be walked to (15 minutes or so) if you are anything near fit.
You'll see an earlier post here on eating out in Arroyo, which should provide food for thought for you.
Benalmadena Pueblo has La Perla and Fidel's restaurants, about 100 yards from La Fonda Hotel, and highly recommended. The hotel school restaurant in La Fonda itself is also worth investigating.
If you want to push the boat out for a special meal during your stay, head for Valparaiso (see link) on the road to Mijas.
Also check out other eateries mentioned in link No 2.
http://www.restaurantevalparaiso.com/
http://www.mijas-villas.com/restaurants.aspx

Take a trip out of town into the hills
Look out for a "venta" usually they are not much to look at but we have tried several (some listed on the links in other posts) and with a few exceptions they have all been excellent not cheap and little english is spoken but well worth a go
often the more remote the better
If you get chance go for a drive through the hills and give them a go but remember the spanish eat either around 2pm or 9 to 10pm

Thanks for the replies. Will certainly be trying a few of those places out.

Mike

you can also follow the road down,as we drive from up there to our place sometimes. enjoy plenty of place on the way down or on the sea front,nice eats on the Marina too