Wouldn't recommend Nigella's recipe ... tried it last Sunday night and it was dreadful ... the evaporated milk/egg mixture sort of scrambled in the oven and it ended up as pasta in a dry, scrambled mixture with no sauce so to speak. 12 mth old DT2 loved it but it was grimaces all around apart from her!!

I usually use a Darina Allen recipe with bacon, onions and mustard & cheddar cheese in a white sauce and it's lovely!

splash of worcestershire sauce works well, in addition to mustard (i use english).

If you can be bothered to rough chop an onion, then put the milk in, bring to simmer, then strain onion back out and use the flavoured milk to make the sauce, that's good too - like a bechamel sauce.

Peppercorns and bayleaves are good with the onion too.

If desperate, a tiny amount of marmite can lift a cheese sauce too.

I use gruyere, parmesan and half a pot of marscapone cheese.. also c 5 chopped tomatoes (minus skin and seeds) and about 3 slices of ham. Yummy.

Haven't had a go myself yet but Nigella's macaroni cheese looks good and easy.
Would also add my vote for mustard in any cheese sauce - powdered for preference. You don't taste it as such - it just makes the cheese more cheesy!

I add a bit of ground nutmeg to my white sauce.

I make my mac cheese sauce from creme fraiche ( the lower fat variety). Just chuck it in a pan with a knob of butter, warm through and slowly add the cheese until it melts in. No lumps like with flour. Much more flavoursome in my opinion!

I think i might have some Gruyere cheese at home. is it pale and a little crumbly?

Love that website Port and lemon, will use that recipe tonight!

Yes, you should add salt to the water. Pasta tastes much better if you do.

How much cheese are you adding to the sauce? I use loads. Also, to sharpen it up a little, try adding the juice of half a lemon

When you have finished making it, and stirring the cheese sauce into the pasta, turn it into an oven dish, sprinkle more cheese on the top and bake until the additional cheese is well browned.

Gruyere cheese gives a lovely flavour. I also add dijon mustard and lots of nutmeg.

Sometimes add leeks and bacon as well as per the mighty Delia.

I use this recipe -- it's the mustard that helps, I think.