Cacio e pepe with Lemon

Directions

1. Bring 3 quarts of water to a boil in a 5qt pot, season with salt.
2. Add pasta and cook, stirring occasionally until about 1 minute before indicated on cooking time of pasta which is printed on the pasta bag.
3. Drain, reserving 1/4 cup pasta cooking water.
4. Meanwhile, melt half of the butter in large pan over medium heat. Add pepper and cook, swirling pan, until toasted, about 1 minute.
5. Add pasta water and lemon juice to pan and bring to a simmer.
6. Add pasta and remaining butter. Reduce heat to low and add grana Padano cheese stirring and tossing gently with tongs until melted.
7. Add pecorino cheese, stirring and tossing gently until cheese melts and coats pasta. If you see the pasta is dry, add a touch more pasta water.
8. Grate lemon zest in and gently toss again.
9. Transfer to a plate and serve. Add sea salt to taste.