For the marinade: I have used quality virgin oil, salt, pepper, lemon zest, lemon juice, garlic and herbs on your choose.
Marinade the shrimps in the marinade for 20-30 minutes.
In a large pot, boil the water and cook spaghetti al-dente.
In a large frying pan melt 2-3 tablespoon of butter, with some drops of oil to avoid burning.
Add the mashed garlic and cook for some minutes.
Add the shrimps and cook until they change the color from pale rose to red ones (usually 2-4 minutes on each side). Season with sea salt if needed. I also use a good glass of dry white wine, as it goes so perfect with this dish. After it has evaporated, add the cream and stir.
When the sauce is ready, toss them in the drained pasta. Make sure that the spaghetti has absorbed all the flavors and made a tasty combination.
Add cilantro and parmesan for the final taste and look.