Preheat oven to 150C. Process biscuits in a food processor until finely crushed. Add butter. Process to combine. Spoon into a 12cm x 34cm rectangular fluted tart pan, with removable base. Press over base and sides of pan. Place in the fridge for 30 mins to chill.
Meanwhile, place the cream cheese, sour cream, lemon juice and lemon rind in a food processor and process until smooth. Add eggs, caster sugar and 1 tbs of the Pimm’s and process until smooth.
Pour cream cheese mixture into the base. Bake on a baking tray for 30 mins or until just set. Turn oven off. Cool in oven, with door ajar, for 1 hour. Place in the fridge for 2 hours or until chilled.
While the cheesecake is baking, place remaining Pimm’s, extra caster sugar and 2 tablespoons water in a small saucepan over medium heat. Cook, stirring, for 2 mins or until sugar dissolves and syrup thickens slightly. Transfer to small bowl. Place in the fridge to chill. Use an electric mixer to beat cream and icing sugar in a bowl until soft peaks form. Spoon over cheesecake. Arrange the cucumber, strawberry, mint and orange zest on top. Drizzle with syrup.