Start by getting your pasta to a boil in a pan of salty water, by the time it’s done the sauce will be ready.
Separate your egg yolks into a bowl and add the zest and juice of 1 lemon before throwing in a good pinch of salt, 1 tsp of black pepper, and grated parmesan. Mix well into a loose paste.
Add a ladle of pasta water to a large mixing bowl, swirl it around a bit, and then pour it out.
Once the pasta is al dente, drain it and add it to the warm bowl along with the egg mix. Stir well, adding splashes of pasta water until you have a creamy emulsified sauce. Taste and then add as much juice of the second lemon as needed.
Serve with a little more parmesan, pepper and lemon zest.