Pretty much any kind of cheese can be used to make a cheese sauce to accompany pasta and vegetable dishes, one of the most famous being Bechamel. Ingredients typically used are flour, milk, butter, eggs and spices like nutmeg and pepper. Cheese in sauces sometimes curdles if cooked over too high a temperature, particularly if mixed with eggs. This doesn't necessarily mean you have to discard it, as there are a few things you can do to uncurdle it, however note these methods might not work if the cheese is extremely curdled.
Strain the mixture through a sieve so that the curdled bits stay behind. This will only work if the cheese is only slightly curdled, otherwise you will be left with next to nothing.
Remove the mixture from the heat and stir very vigorously until the cheese curds have dissolved into the sauce.
Place the mixture in a food processor and blend till smooth.
Remove from the heat and add a little cornflour and water to thicken the sauce you're making with the cheese. While this thicker sauce won't uncurdle the cheese, it will help to hide some of the curdles.