In a large mixing bowl, mix the orange juice with the egg yolk, honey and vanilla essence. Stir in the cooked rice, raisins and toasted walnuts.
In another bowl, whisk the egg whites until soft peaks form, then carefully fold into the rice mixture with a large metal spoon.
Pour into four ramekins that have been lightly coated with vegetable oil spray or lightly greased with vegetable oil.
Place the ramekins in a baking dish. Carefully add boiling water to the dish to a depth of 2.5 cm. Bake for 30–35 minutes or until the puddings are just set. Serve hot.