Bring a large pot of water to a boil, and add a small handful of salt - it's very hard to over-salt pasta water. Meanwhile, roll the lemon between your hand and the counter to get the juice flowing, and zest it with a grater.
Add the pasta to the boiling water.
When it is about 6 minutes away from done, add the peas.
When the pasta is done, drain it and the peas and return them to the pot.
Add about 2 tablespoons of butter and a bit of olive oil, and the lemon zest.
Stir vigorously to help the butter melt and coat the cheese.
Add a good pinch of salt (you can add more to taste later) about 10 grinds of pepper, and grate in as much cheese as you like—at least a handful.
Stir vigorously, so that the cheese distributes instead of clumping.
Taste and adjust seasoning.
Enjoy!