Macaroni cheese goes under the grill until the top blisters

On a wet Tuesday at the end of November, when the windows steam up before six o'clock, I make macaroni cheese. Nobody at my table ever says no to it. It is the kind of supper that needs nothing clever: pasta, milk, butter, flour and a good lump of mature Cheddar. But there is one habit that turns it from a soft pale bowl into something people fight over, and it happens in the last five minutes. Once the dish is hot, I slide it under a hot grill and leave it there until the top blisters, bubbles and goes golden brown at the edges.

I start with the pasta, because it needs a head start. For four of us I use 300 g of macaroni and cook it in a big pan of well-salted water, but I take it off two minutes before the packet says. It will keep cooking in the sauce and again under the grill, and fully cooked pasta turns soft and swollen by the time it reaches the plates. I drain it, give it a shake and leave it in the colander while I make the sauce.

The sauce is a plain white sauce done slowly. I melt 50 g of butter in a saucepan on a medium hob, stir in 50 g of plain flour and let it cook for a minute or two, until it smells a little like biscuits. Then the milk goes in, 600 ml of it, a splash at a time at first, whisking out every lump before the next splash. When it is all in, I keep stirring until it thickens and coats the back of the spoon. Only then do I take it off the heat and stir in most of the cheese, about 200 g grated, with a teaspoon of hot mustard and a good grating of black pepper. The mustard does not make it taste of mustard; it just makes the cheese taste more of cheese.

I fold the drained macaroni into the sauce, tip everything into a buttered ovenproof dish and scatter the last 50 g of cheese on top, with a handful of breadcrumbs if there are any stale crusts in the bread bin. If the pasta and sauce are still steaming, the dish only needs a few minutes. If I have made it ahead and it has been in the fridge, it goes into the oven at 200°C (180°C fan, gas 6) for about 25 minutes first, until it is bubbling at the sides and hot right through the middle.

Then comes the grill. I turn it up high, put the dish on a shelf a hand's width below the heat and stay in the kitchen. This is not the moment to go and fold the washing. In three or four minutes the cheese on top melts, puffs into little blisters, then browns, and the edges of the pasta that poke through turn crisp and almost crunchy. I turn the dish round once so one corner does not burn while the other stays pale. When it looks like the picture you had in your head, it comes out, and I leave it to stand for five minutes so the sauce settles and nobody burns their mouth.

A soft bowl and a blistered one taste like two different suppers. Underneath, the sauce stays creamy and loose; on top there is a lid of browned cheese that cracks when the spoon goes in. Everyone wants a corner piece, so I have learned to use a wide, shallow dish rather than a deep one. More top means more crust for everyone.

If there is some left, I let it cool, cover it and put it in the fridge within two hours, as the Food Standards Agency advises for leftovers, and we eat it within two days. When I reheat it, I add a splash of milk, heat it until it is steaming hot all the way through, and reheat it only once. Then it can have one more minute under the grill. Contains milk and wheat (gluten), and mustard.

So that is my small November habit: cook the pasta a little short, make the sauce slowly, and do not take the dish out until the top has blistered. Do you have a corner-piece person at your table too?