2) Meanwhile, heat the olive oil in a large frying pan. When almost smoking, add the shallots and garlic and saute until soft and translucent, about three to four minutes, being careful not to burn the garlic.
3) Add the clams and wine. Cover and simmer for six to eight minutes or until most clams have opened. Add two tablespoons of chopped parsley. Whisk in the butter to thicken the sauce slightly.
4) Drain the pasta in a colander. Do not rinse it with water - this will remove the natural starches. Place the pasta into the clam pan and mix thoroughly. Check seasoning.
5) Pour the pasta into a large serving bowl. Zest lemon over the dish, being carefull not to zest the white part of the lemon, which is bitter. Garnish with remaining parsley. Serve immediately.