Boil a large pot of water and the 1.5 Tbsp. of salt
In a large bowl, whisk together butter, cream, Kosher salt, Parmesan cheese and whisk together.
Add the egg yolk and whisk vigorously to ensure it doesn't curdle.
Cook the pasta in your water until it is al dente, usually 8-10 minutes
When the pasta is done, reserve one cup of pasta water and then drain the rest of the pasta.
Immediately whisk the hot pasta water into the cream and egg mixture. Add just a bit at a time and whisk vigorously the entire time to keep the egg yolk from curdling.
Once pasta is drained, add it to the bowl with the creamy lemon mix and mix well.
Add in the parsley and mix to distribute it.
Add to a platter and top with thyme, crispy sage and more salt and pepper to taste. Serve immediately.