In a large saucepan, bring
water to the boil and add the macaroni and salt. Boil it uncovered until
it is just tender but not overcooked (about 8 minutes).
Preheat a moderately hot oven 180°C.
Drain the macaroni thoroughly, put it back into the same hot saucepan it was cooked in and mix in the butter.
Grate the cheese and mix it in with the macaroni a bit at a time, while it is still warm.
Whisk the egg until fluffy and add the milk, onion powder, white pepper, salt, pepper sauce and mustard. Pour in with the macaroni and mix.
Place in a greased oven proof casserole dish (we used individual ones). Top with a little butter, some grated cheese and fine breadcrumbs.
Bake in the centre of the oven for about 30-45 minutes depending on the depth of the dish.