Step 1

Bring a pot of water to a boil and add some salt to the water (not too much, as you will use this water for your sauce). Add the pasta and cook according to package instructions. Reserve 1/2 cup pasta water, then drain.

Step 2

In the same pot the pasta was boiled in, add 1/3 cup of the pasta water. Melt your butter into this and add the pepper. Return the cooked pasta to the pot and toss to coat.

Step 3

Add the cheese and egg yolk and, using tongs, toss the ingredients together until combined. If the pasta seems a little sticky, add the remaining pasta water. If it's a little wet, add more cheese. Taste for seasoning and adjust as necessary.