Bring a large pot of water to a boil and add salt to the water.
Cook the pasta until al dente. (tender but still has a bite)
Drain the pasta (reserving some of the pasta water)
Place the pasta in a large, heated bowl
Add in the diced butter and grated cheese and start tossing the pasta until the butter and cheese have melted, add a little of the pasta water as necessary to keep the mixture loose.
Season with salt and pepper to taste