Paltrow’s swan-necked, elegant mischievousness is just one delicious flavor (albeit the most important) in McGrath’s very tasty ensemble. Jeremy Northam’s Mr. Knightley – the gentlemanly Mr. Right she is too obtuse to recognize – captures Austen’s most admirable hero with just the right note of diffident strength. They’re a great romantic match. Purists may feel that Toni Collette is a bit too old to be the naive Harriet, and that Alan Cumming’s Reverend Elton, whom Emma has targeted to marry Harriet, isn’t handsome enough, but in the face of such delightful performances, why quibble? The great Juliet Stevenson is hilarious as the self-enamored Mrs. Elton; Sophie Thompson artfully blends silliness and pathos as Miss Bates, and ““Trainspotting’s’’ Ewan McGregor cuts a dashing figure as the flirtatious Frank Churchill. Sumptuously appointed and filled with wonderful talk, ““Emma’s’’ unforced charm is a remarkable achievement for a first-time writer-director. The Texas-born McGrath, who co-wrote ““Bullets Over Broadway’’ and started out as a ““Saturday Night Live’’ writer, may seem an unlikely medium for Austen’s 19th-century comedy, but he proves to be to the manner born.