you can really use any cheese U want ......I tend to go for the Stronger tasting cheese... and I like to top with tomatos after i have put the grated cheese on top .....you can also use bacon or breadcrumbs .....I also use lots more cheese than I have put in recipe .....but its up to you to add what u want .... The colemans mustard in the sauce ..really does make a difference ......
Ingredients
250g/9oz macaroni
40g/1½oz butter
40g/1½ plain flour
teaspoon of colemans dry mustard
600ml/1pint 1½fl oz milk
250g/9oz grated strong mature cheddar
100g/4oz grated Parmesan or Asiago cheese
salt.. black pepper.. paprika and Garlic salt
1 large tomato sliced thinley
Method
1. Cook the macaroni in a large saucepan of boiling salted water for 8-10 minutes; drain well and set aside.(i also add a touch of olive oil to prevent sticking
2. Melt the butter over a medium heat in a saucepan slightly larger than that used for the macaroni. Add the flour and stir to form a roux, cooking for a few minutes. add the mustard in
3. Gradually whisk in the milk, a little at a time. Cook for 5-10q minutes to a thickened and smooth sauce.stirring all the time to avoid lumps
4. Meanwhile, preheat the oven to about 350 elec
5. Remove the sauce from the hob, add a touch of salt black pepper paprika and garlic salt then 175g/6oz of the cheese and stir until the cheese is well combined and melted.
6. Add the macaroni to the sauce and mix well. Transfer to a deep suitably-sized ovenproof dish.
7. Sprinkle over the remaining cheddar and the Parmesan or Asiago top with the sliced tomatos and place the dish in top part of the oven Cook until the cheese is browned and bubbling.

In this picture I had part cooked it ..... we finished it off at the party so it was nice and golden brown and bubbling .....
Enjoy......
ps The mac and cheese in picture was made for 12 people ....The recipe above is for 4......