To make the curd, place all ingredients in a bowl and whisk to combine. Place bowl over a saucepan of gently simmering water and whisk until thickened. Remove from heat and set aside.
To make the meringue, place egg whites, sugar and balsamic vinegar in a bowl and whisk to combine. Place over a saucepan of gently simmering water and whisk until soft peaks form. Transfer to an electric mixer and continue to whisk until stiff peaks form. Set aside.
To make the sable, place all ingredients in a food processor and process until a dough forms. Turn out onto a floured bench and roll dough to 5mm thick. Transfer to a baking tray and place in the oven to bake until golden, about 15 minutes. Remove from the oven and set aside.
To make the cream, combine ingredients in a bowl and whisk to medium peak. Transfer to a piping bag and pipe onto a paper lined tray to 10cm lengths. Place in a freezer until set.
To make the reduction, place vinegar and sugar in a saucepan and bring to a boil over medium heat. Allow to simmer until reduced to a thick glaze. Remove from heat and set aside.
To serve, place some curd on each plate. Break over some sable and pipe on some meringue. Add frozen cream and garnish with orange segments, grapefruit segments and lime zest.