Spaghetti with clams is very different from spaghetti with clam sauce. The former is a dish with a light, fragrant dressing tossed with whole clams; in my opinion, it’s the only way to make this dish. It’s also beautiful on the table; there’s something about the shells combined with pasta that just looks so satisfying. And satisfying it is. You could also use mussels, for a twist, or small New Zealand cockles, whose refined shape and delicate flavor make for a more elegant version.
Bring a Large Pot of salted water to a boil. Add the spaghetti and cook until tender but still firm to the bite, stirring constantly in the beginning to prevent it from sticking together, about 8 minutes.
Meanwhile, in a large sauté pan, heat the oil over a medium-high flame. When almost smoking, add the shallots and sauté until soft, about 3 minutes. Add the garlic and sauté until the garlic is golden brown and the shallots are translucent, about 3 minutes (being careful not to burn the garlic). Add the clams, wine, 2 tablespoons of the parsley, and ½ teaspoon each of sea salt and pepper. Cover and simmer until most of the clams have opened, about 6 minutes (discard any shellfish that do not open). Whisk in the butter to thicken the sauce slightly.
Drain the spaghetti, reserving ⅓ cup of the cooking liquid. Do not rinse the spaghetti with water; you want to retain the natural starches that help the sauce adhere to the spaghetti. Toss the spaghetti with the clam mixture in the pan to coat. Add enough of the reserved cooking liquid to moisten.
Transfer the pasta to a large serving bowl. Sprinkle the lemon zest over the pasta. Garnish with the remaining parsley and serve immediately.