Those big, juicy, rare half-pound sirloin burgers just won't do the trick when you're jonesing for some sliders. Miami has no White Castles (even the southern chain Crystal has only made it as far south as Broward County), but who needs em when we've got the last surviving Royal Castle? Now independently run, the 24/7 dinerette serves a variety of items including fried chicken with thin, crispy batter; belly busting breakfasts featuring three-egg omelets, smoked sausages, grits, hash browns, fried catfish fillets, and authentic country ham; even vegetarian burgers for those who must. But the two-bite beef burgers, cooked when you order them (not steamtabled) in darned good grease are the piece de resistance. With cheese or without, they're cheaper by the six pack -- and nobody can eat just one of these succulent, sautÃ©ed, onion-topped, square patties. To wash it down: the Castle's signature birch beer, served in a frosted mug just like in the Forties.