Heat the milk and butter in a saucepan until the butter melts. Do not let the milk boil. Add the lemon zest and remove the pan from the heat to cool slightly.

Whisk the egg yolks and 50g of sugar in a bowl. Slowly pour the warm milk over the egg mixture while whisking constantly. This keeps the eggs from scrambling.

Place the fresh breadcrumbs into a large mixing bowl. Pour the custard mixture over the crumbs and stir gently. Let it sit for 10 minutes so the crumbs soften and expand.

Grease your baking dish with a little butter. Pour the breadcrumb mixture into the dish. Bake at 170°C for about 25 to 30 minutes until the custard is set and firm.

Put the jam in a small bowl and stir it until it is smooth. If it is too thick, heat it in the microwave for 20 seconds. This makes it easy to spread.

Remove the pudding from the oven. Spread the softened jam carefully over the top of the warm custard. Try not to break the surface of the custard as you spread.

Put the egg whites into a clean, grease-free bowl. Whisk them with an electric mixer until they form stiff peaks. They should look like fluffy white clouds in the bowl.

Add the 175g of caster sugar one tablespoon at a time. Keep whisking until the mixture is thick, glossy, and holds its shape well. This creates a stable and sweet topping.

Spoon the meringue over the jam layer. Use a fork to pull up little peaks for a pretty look. Make sure the meringue touches the edges of the dish.

Put the dish back into the oven for 15 minutes. Bake until the meringue is pale golden brown and crisp on the outside. Serve it immediately while it is warm.