Bring a large pot of water to the boil. Add macaroni and cook per packet directions MINUS 1 minute.

Drain macaroni, return to pot, add butter and toss until melted. Set aside to cool while making the sauce.

Mix together the topping ingredients (panko breadcrumbs, melted butter, and salt) and set aside.

Preheat oven to 180?C/350?F.

In a large saucepan or ovenproof skillet, melt butter over medium heat. Add flour and cook, stirring constantly, for 1 minute.

Add about 1 cup of milk and mix to dissolve the paste into the milk. Then add the remaining milk and mix until lump free.

Mix in salt and any optional seasonings if using.

Cook, stirring regularly, for 5?8 minutes until thickened to a cream consistency.

Remove from stove, add cheese and stir until combined (cheese doesn't need to melt).

Pour the sauce into the pot with macaroni. Stir quickly, then pour back into the skillet or a baking dish. Sprinkle with breadcrumb topping.

Bake for 25 minutes or until the top is light golden.

Serve immediately.