Preheat the oven to 220ºC / 200ºC Fan / Gas 7. Melt the butter in a pan, add the flour and garlic then keep stirring to form a roux.
Meanwhile bring a large pan of salted water to the boil then add the macaroni and cook for 10 minutes until a little under al dente.
Add the bay leaves to the roux followed by the milk, stirring continuously until no lumps remain and the mixture thickens. Add the Dijon mustard, cheese, cream (if using) and finally the pigs in blankets. Season to taste then transfer to an oven proof dish.
To make the breadcrumbs, combine all the breadcrumb ingredients in a clean bowl with a generous seasoning of salt and pepper. You can add more cheese, pickled walnuts and parsley at this stage to suit your taste. Scatter the breadcrumbs over the top of the macaroni cheese then pop in the oven for 10-15 minutes until the top is crispy and golden.