Your arrive time at 12 is tricky. This means you have until about 1:15pm to eat in a restaurant, as restaurants in France are closed between mealtimes. I imagine that even with the most miraculously smoothest exit, you will get out of the airpot in 30 minutes, then get your rental, etc. Not much lunch-time left by then.
If the weather is nice, one lovely solution would be to have a late picnic lunch at the very charming city of Sète with all its canals, and get the local specialty "Tielle" - a kind of folded pizza that is biscuity-crispy outside, with runny creamy coquille St Jacques inside, and very slighly spicy. Le Paradiso at 11 Quai de la Résistance makes it very well and is open all afternoon. Its location right on one of the nicest canals - with underground parking ! - gives you good options to picnic by the water. -- Don't forget to pack a minimum picnic kit, with plastic forks and knives.
For a long shot, this great seafood restaurant is in the lovely lakeside village of Bouzigues. Les Demoiselles Dupuy, open until 3pm.
Address: Chemin de la Catonnière, 34140 Bouzigues
tel: 04 67 43 87 34, or, if you're calling from a non-French phone: +334 67 43 87 34. Here you must reserve.
If you can't make it on your first day, you may consider going later to this secret kind of adress. I love pèzenas and have stayed several times there but have not found outstanding restaurants there. Renting a house is a good solution. Might as well get all the goodies from its nice compact market and make good meals at home.
Have a grand time.
