Warm the milk in a pan with the butter and lemon rind.
Lightly whisk the egg yolks with 1 oz (25 g) of the sugar and pour in the milk, stirring well. Strain the custard over the breadcrumbs in a greased 2-pint (1 litres) ovenproof dish and leave to stand for 15 minutes.
Bake at gas mark 3, 325°F (170°C) for 25 minutes, until lightly set. Remove from the oven and spread the top with the warmed jam. Whisk the egg whites until stiff, add half the sugar and whisk again until thick and glossy. Fold in the remaining sugar with a metal spoon. Pile the meringue on top of the pudding and bake at gas mark 4, 350°F (180°C) until the meringue is lightly browned.