• Preheat your oven to 180c (350f)

For the panko crumbs

• Melt the butter over medium heat for 3 - 4 minutes, swirling the pan until it browns then take off the heat and mix into the panko crumbs straight away. It's hard to tell how much butter will evaporate for you so I used 50g of the melted brown butter with the crumbs. (see notes)
• Add the thyme leaves in and then set the crumbs aside.

For the pasta

• Cook the macaroni according to the instructions but undercook it by a minute.
• Drain and mix with the tablespoon of butter and set aside.

For the sauce

• Melt the butter in a medium saucepan over medium heat until it starts to sizzle.
• Add the flour and whisk vigorously for a minute.
• Lower the heat slightly and add the milk in a slow stream, whisking the whole time making sure you get all the flour mixture from the sides of the pan.
• Cook for a few minutes until it thickens slightly and coats the back of a wooden spoon.
• Add the cheese in 3 or 4 lots, whisking and letting it melt in between each addition.
• Add the nduja and whisk to combine.
• Taste! You can add more nduja if you wish and also season with salt and pepper. It might not need any salt but I like to add a few cracks of black pepper here.

Baking the mac and cheese

• Mix the pasta into the sauce and pour into a baking dish. I used a 9 x 9 inch metal pan
• Sprinkle the panko crumbs in an even layer over top and bake in the oven for 25 minutes until bubbly and slightly golden on top. Don't bake it for longer as the sauce can get too soaked up.
• Let it sit for a few minutes before serving then dig in!