Bring a large pot of water to a boil. Salt heavily and add in your spaghetti.
In a large pan, melt your butter over low heat. Remove about 1/2 cup of pasta cooking water and add this in. Add in your lemon juice.
When the pasta is almost al dente, add to the butter lemon sauce mixture.
Toss and add in a bit more pasta water if need be to finish cooking the pasta and to loosen the sauce.
Toss in your cheese and lemon zest, reserving a little of each for garnish
Once the pasta is done remove and serve immediately garnished with extra lemon zest and cheese.
