2. Place the butter, oil and grated lemon zest in a large non-stick pan. Remember to save some of the zest to add at the end.
3. Melt the butter and sauté it. Stir well with a wooden spoon and add the lemon juice. Finally add the garlic clove. Simmer on low heat for about 5 minutes.
4. Meanwhile, cook spaghetti in 1.5 liters (7 cups) of water with 1/2 tablespoon coarse salt.
Take a look at the cooking time of the spaghetti on their package. Halfway through cooking, drain spaghetti and place in skillet with lemon sauce.
Spaghetti should be very much al dente, practically still raw, and finish cooking in the pan with the sauce.
5. Add a ladleful of the starch-rich cooking water. Finish cooking the spaghetti in the pan, stirring well. If necessary, add a little more water.
Serve hot with more lemon zest and a little chopped parsley on top