Scantly cover clams with water to a large stock pot. Bring water to a boil and cook clams for about 5–10 minutes until they are wide open. Husk the clams and reserve cooking liquid.
Heat olive oil in a wide saucepan. Add garlic and sauté until fragrant, about 30 seconds. Add clam broth, allowing it to reduce while you chop tomatoes. Add tomatoes and their juice to the garlic and broth, then reduce further. Add oregano and red pepper flakes “until sauce is done.”
Bring water to boil in a large stock pot. Salt and cook pasta according to package instructions before draining and returning to the pot or a serving dish. Toss with clam sauce and garnish with chopped parsley to serve.