Soak the apricots in mineral water overnight.
Preheat the oven to 180°C (350°F).
Butter a 1½ litre souffle dish.
Soak the sultanas in hot water for 10 minutes, then drain and mix with ⅓ of the apricots. Reserve the rest of the apricots and their soaking liquid for the sauce.
Remove the crusts from the bread and cut into triangles.
Line the sides of the souffle dish with the bread, buttered side up, and layer the remaining bread in the dish with the sultanas, apricots, and a sprinkling of nutmeg or cinnamon.
In a saucepan, heat the milk, cream, and ⅔ (4oz) of the caster sugar to boiling point. Remove from the heat, add a few drops of vanilla (½ tsp), and stir in the beaten eggs.
Pour the milk mixture over the bread and let it soak for a few minutes.
Cover the dish with foil and place it in a large, deep roasting tin. Pour boiling water around the dish so that it comes halfway up the sides.
Bake for 50 minutes or until set and firm. Remove from the oven and allow to cool slightly before turning out onto a serving dish.
To make the sauce, place the remaining apricots and their soaking liquid into a saucepan and simmer for around 15 minutes. Add the remaining sugar and lemon juice, and stir until dissolved. Blend the mixture in a liquidizer until smooth.
Serve the pudding with some fruit sauce.