It just appeared, as if out of nowhere one day there was no Sardinia Enoteca Ristorante in South Beach, the next day there was. And the day after that the 96-seater was packed to the gills, and hasn't seen an empty chair since. While "party hearty" is the draw for many a SoBe dining establishment, it is Sardi-hearty fare, rustic and robustly flavored, that has lit the fire of the public's fancy here. Lighting the smoky fire of a roaring open hearth are logs of wood beside which you'll find roasting baby suckling pigs, pancetta-wrapped quail, baked baby octopus, peasant-style stews, and Black Angus rib eye steaks. Sardinia offers a surplus of enticements unique to South Beach restaurants, among them olives with wild fennel flowers, boar sausage, chestnut honey, Italy's diverse cheeses, Sardinia's distinctive wines, professional service, and affordable prices most pastas are $14 to $24; main courses are in the midtwenties range. There are no reservations accepted, so take advantage of a less-crowded lunch hour, or take your place in line.