Simmer the rhubarb with the vanilla pod, caster sugar and the zest and juice of the orange for 8-10 mins, or until the rhubarb is soft but holds its shape. Set aside.

Beat the egg with the milk in a shallow dish, add the bread and leave to soak for 1 min, turning once.

Fry in the butter over a medium heat for 4 mins, then flip and cook for 4 mins more, until golden on both sides. Top with the rhubarb and warm custard.