Dwayne Beliakoff’s serially delayed “fast slow food” restaurant has finally opened in a modernist glass box in Director Park on the South Park Blocks, just adjacent to a strangely gonadal fountain devoted to the spirit of teaching. Despite Violetta’s über-sleek exterior, its insides are a clean, inviting Westy-lefty version of an East Coast urban burger-and-dog microshop, with terrifically specific recycling instructions decorating the waste bins. The signature Angus beef Violetta Burger ($6) is accordingly a sloppy, tasty mess to rival anything in South Philly or the old Coney Island—sealed shut by its own juice and fat in recycled cardboard and paper—with appealingly goopy special sauce, butter lettuce and something called “10-hour” tomatoes. Applewood bacon and cheese can be added, at minor expense, for even greater decadence. Violetta is a welcome lunch-dinner presence in a neighborhood that suffers from an appalling absence of affordable sit-down options.