Preheat the oven to 180°C (160°Fan / Gas Mark 4).
Bring a large pan of salted water to the boil. Cook the macaroni according to packet instructions. Drain and set aside.
Meanwhile in another large pan, melt the butter over a medium heat.
Add the chorizo and garlic and fry for a minute to release the chorizo oils.
Stir in the flour and cook for 2 minutes, stirring all the time.
Gradually add the milk, turn up the heat and whisk until the sauce thickens. It should coat the back of a spoon. This usually takes a couple of minutes.
Take the sauce off the heat and add the grated cheddar, mozzarella, smoked paprika, cayenne pepper and Dijon mustard. Stir until the cheese melts into the sauce.
Add the cooked pasta to the cheese sauce, mix together, and spoon into an ovenproof dish.
Sprinkle over the panko breadcrumbs and parmesan, and bake in the oven for 20 minutes until golden and bubbling.