Whisk egg, honey, buttermilk and zest in a large bowl. Stir in flour and meal until smooth and combined.
Pour the batter into a round greased baking dish. Evenly scatter the cornflour over the batter. Place juice, boiling water and sugar in a jug and stir to combine.
Preheat the oven at 200’C for 10 minutes. Carefully pour over the pudding mixture. Bake for 35 minutes until golden and firm to touch. Remove from oven and serve warm with pouring cream.