The American immigrant experience is certainly compelling material for filmmakers, with centuries of rich tradition and robust narrative. Not that you’d know this after watching Nick Agiashvili’s A Green Story, which comes across like the result of a not particularly inspired Mad Lib: “Penniless yet ambitious [Greek] immigrant comes to America, clawing his way up from [homelessness] to start a company making [eco-friendly cleaning products], his obsession costs him his [first marriage] but ultimately leads to [financial success] before running afoul of [Big Soap] and dealing with a far more personal crisis: [terminal cancer].” Even worse, this formulaic narrative is based on a true story. After witnessing the horrors of World War II on his native Crete, Eftichios Vlahakis (Ed O’Ross) emigrates to the U.S., changes his name to “Van,” and founds Earth Friendly Products. His dreams of green laundry soap in every high-capacity washing machine are imperiled by his evil competitor (we assume he’s evil; he’s played by Malcolm McDowell) and a fatal diagnosis. But for a biopic, none of it registers as particularly authentic: not O’Ross’s generic, more-Slavic-than-Greek accent, not the schlumpy Van’s unlikely mack-daddy-ness, and not Shannon Elizabeth’s “acting.” Agiashvili plods back and forth from young Eftichios’s first months in America to Van’s attempts to close that one big deal before kicking the bucket. Honestly, Vlahakis’s tale should be compelling, but a weak script and mostly dull performances (one exception: Billy Zane . . . I know!) make A Green Story more monotonous than mythic.