Spaghetti al limone & pepe

INGREDIENTS
1 Box of pasta (450 Gr.) spaghetti, spaghettini, bucatini also work well
70 Gr. Butter (equivalent of 5 tablespoons)
1 Clove Garlic finely minced
30 Gr. Grated Parmesan Cheese
1/2 Teaspoon freshly ground pepper
Zest and juice of a lemon
Pinch of Chilli flakes (optional)

METHOD
In a medium pot of boiling salted water, cook the pasta until al dente.
Cooking the pasta in a smaller volume of water that the recommended large pot, produces a starchier water, which helps to better emulsify the sauce.
Reserve a cup and half of starchy pasta water, then drain pasta.
In a medium size skillet melt the butter at low temperature and stir in the garlic, cook for a minute or so, so the garlic infuses the butter. Add the lemon zest and mix well.
Using the same pot, return the pasta and pour the garlic-lemon zest butter to the pot and mix well. Add about half the pasta water and the lemon juice increase the heat to medium-high and cook, stirring and tossing to coat, till the pasta is glazed and has a satiny finish. Add the pepper and mix well.
Add the 3/4 parmesan cheese and mix well.
Serve in a bowl – Garnish with the remaining Parmesan and a good dash of ground pepper.