If you're Puerto Rican you know better than to venture out to a restaurant to eat comida criolla. Nobody makes better arroz con gandules than your abuela, nobody's alcapurrias are quite as tasty as mami's, and mofongo -- well forget it -- you just can't get good mofongo off the island. Until now. This past December Puerto Rican singing-sensation-superstar Ricky Martin joined the owners of Ajili Mójili, one of San Juan's most noted restaurants, and opened Casa Salsa here in South Beach. Everything at Casa Salsa, from the interior design (corrugated metal, cane, wood, and straw with a SoBe twist) to the live plena music, the art work, and, of course, the food, will take you back to the sweet, lulling rhythms of la isla del encanto. Although everything we sampled was delicious, including the items that seemed to be more SoBe Rican than anything, for a true gustatory excursion through Puerto Rico we recommend sticking with the traditional dishes: surullos, alcapurrias, asopao, arañitas, and arroz con gandules. The dish Casa Salsa does best is mofongo: plantains mashed with oil and garlic and filled with your choice of chicken, lobster, or beef, and topped with a delicious tomato-based salsa, all served in a typical wooden pilón. ¡Ay que rico! Lunch daily from noon until 4:00 p.m. Dinner Monday through Thursday from 6:00 p.m. until midnight, Friday through Sunday until 2:00 a.m. Reservations are strongly recommended for Friday and Saturday nights: You probably won't get a table without one.