Bring a large pot of Water to a rolling boil, then add a generous pinch of Fine sea salt.
Add the Fresh egg fettuccine and cook until just al dente according to package directions (usually a few minutes); before draining, reserve about 1 cup of the starchy cooking water.
Reduce heat to low and melt the Unsalted butter in a large skillet, stirring until it’s foamy but not browned.
Add a splash of the reserved pasta water to the butter and whisk briefly to form a smooth, silky emulsion.
Remove the skillet from the heat and quickly add grated Parmigiano Reggiano, tossing to combine; add more reserved pasta water a little at a time until the sauce reaches a creamy, clingy consistency.
Return the drained fettuccine to the skillet and toss gently until every strand is coated, seasoning to taste with additional fine sea salt if needed.
Serve immediately, finishing with an extra grating of Parmigiano Reggiano for a bright, salty finish.
