Legend has it that back during the Gold Rush, in the boomtown of Placerville (also known as Hangtown, for its frequent rough-justice necktie parties), a prospector grimy with the mud and dirt of the Sierra foothills yet nouveau riche staggered into the first restaurant he saw and ordered "the most expensive thing on the menu." In those days, in that place, oysters were a barely rumored delicacy and eggs were a buck apiece, so the two were combined into a dish that has since become a Northern California classic. A most appropriate place to sample it is the Tadich Grill, which began business in the annus mirabilis of 1849 at Portsmouth Square, then the bayside transfer point for seafaring argonauts heading up the Sacramento River. Nowadays this venerable, polished-walnut dining hall is located in the Financial District, but Hangtown Fry is still a specialty of the house. Half a dozen plump, lightly breaded oysters and long strips of chewy bacon are wrapped up in a moist egg frittata with a delicate outer crust, and the result -- sweet, supple, and smoky all at once -- is like a fluffy version of angels on horseback. It comes with the establishment's marvelous fried "long branch" potatoes and that crusty San Francisco sourdough that's been around as long as Hangtown Fry and the Tadich itself.