4 to 5 dozen clams (top neck to the smaller middle neck clams).
¼ cup water
1 cup dry white wine
1 lb spaghetti
¼ cup extra-light olive oil or avocado oil
1 small yellow onion or shallot, finely diced
4 cloves garlic, thinly sliced
1 t red pepper flakes
1 t fresh oregano leaves
4 T unsalted butter
Juice and zest of ½ lemon
2 T finely chopped Italian parsley
Extra-virgin olive oil, for finishing
Freshly grated Parmigiano-Reggiano cheese, for serving (optional)
Fill a large bowl or with cool water. Add 1 tablespoon of sea salt (not iodized salt) and let the clams sit in the cool water for 20 to 30 minutes, but no more. Gently spoon then into a colander and rinse them a couple more minutes with cool tap water.
In a large pot that you will boil the pasta in, bring water and wine to a boil. Add the clams, cover, and cook for about 5 to 7 minutes, until clams open.
Discard any clams that failed to open.
Pour clams and juice from pot into a large mesh strainer, set over a large bowl to catch the juices. Remove all but about 16 to 20 clams from their shells and roughly chop. Place them in a smaller bowl. Leave the rest of the clams in their shells and place in a bowl, covered to keep warm. Set all three bowls aside.
Meanwhile, in the same large pot, cook the spaghetti 7 to 8 minutes in salted water until al dente. Before draining reserve two ladles of pasta water; pour one over the clams in their shells to keep then warm, and reserve another ladleful (in a glass or cup) to add to the almost-finished clam sauce.
In a large skillet large enough to hold the pasta and sauce, heat the olive oil or avocado oil over medium heat and sauté the onion or shallot for about 3 minutes. Add the garlic, red pepper flakes, oregano, and butter and sauté another minute.
Add the chopped clams, clam broth (pour slowly so that any grit will be left behind), and reserved pasta water. Cook one more minute.
Season lightly with salt and pepper and add the lemon zest and juice.
Add the drained pasta to the pan along with the parsley. Heat for just a minute or two while tossing with a pair of tongs, until well combined.
Divide into 4 warm pasta bowls and garnish each bowl with the clams in the shells. Pour the rest of the hot clam broth from from the skillet over each bowl.
Sprinkle with some of the parsley, drizzle with a little extra-virgin olive oil, and serve with grated cheese, if desired.