South Shore Grill   South Shore Grill is all about cheap, quick food with a gourmet twist. It serves up plate lunches, heaping sandwiches, well-stuffed burritos and salads. The boldly colored interior is all fun, but they're serious about their half-pound burgers topped with chipotle aioli; double-orders of fish tacos, and Caprese salad made with mozzarella. The plates all come with tuna-mac salad and the signature vinegary slaw. Save room for desserts.  3114 Monsarrat Ave. 734-0229, www.hawaiidiners.com. 10:30 a.m.-9 p.m. Mondays-Saturdays; 12:30- 9 p.m. Sundays. Cash only. BYOB OK.  Web site: www.hawaiidiners.com