Find a large saucepan for cooking the macaroni and a colander to drain it, a small saucepan, a wooden spoon and a whisk and a grater for the cheese. Find a
Half fill a large saucepan with water, add the salt and bring up to the boil. Add the macaroni and when the water reboils, simmer for 7 minutes. When cooked, drain, rinse under hot water and set aside ready to add to the sauce. Slice the tomatoes.
Place the butter or margarine in a saucepan and set over a low heat to melt Measure the cold milk into a basin and sift the flour on to it Using a whisk or rotary hand beater, mix the two together very thoroughly.
Pour the blended milk and flour into the melted fat and cook, stirring all the time until the mixture has thickened and is boiling. Simmer for 2–3 minutes, then season well with salt and pepper, add the mustard and half the cheese. Add the cooked macaroni and mix well. Heat through for a few moments, then draw the pan off the heat.
Pour into the pie dish. Decorate the top with alternate rows of sliced tomato and the remaining grated cheese.
Pass the macaroni cheese under a hot grill until bubbling hot and brown. Serve with hot buttered toast or a salad.