What to see: Lyn Gardner's theatre tips
Theatre companies join forces for a Christmas Fayre in Leeds and the RSC gives Roald Dahl's Matilda a musical twistFour of British theatre's most ingenious companies, Unlimited, Slung Low, Belt-Up and Pilot, join forces on Saturday for a Christmas Fayre in Holbeck Underground Ballroom in Leeds. It sounds like lots of fun, and everyone is welcome. The estimable Forest Cafe in Edinburgh " which many of you will know …