There are lots of good restaurants in the area. I can personally recommend the Hotel Vidal in Ceret for great French Bistro meals and the Hostalet de Vives in Vives for Catalan specialties.
For a day at the seaside or a visit to Collioure try the Poisson Rouge in Port Vendres for excellent seafood in a great setting, but please note that they don't take credit cards.
It is always best to phone first and reserve as not all restaurants are open every night.
Hotel Vidal
Hostalet Vives
http://www.hostalet-vives.com/
Le Poisson Rouge
http://lepoissonrouge66.free.fr/