Boil the pasta in a generous amount of lightly salted water. While it cooks, heat the oil in a medium pot set over medium to medium-high heat. Add the onions and garlic and cook until softened, about 2 minutes. Add the wine, stock, pepper, chili flakes and oregano, and bring to a simmer. Add the clams to the pot. Cover and cook just until clams open.
When cooked, drain pasta well and divide among 2 shallow pasta bowls. Surround pasta with clams. Spoon clam cooking liquid over pasta and clams, sprinkle with parsley, and serve.
Note: Discard any clams that do not close when squeezed before cooking, or that do not open after cooking. Both are signs the bivalve is dead and should not be eaten.
Options: Instead of spaghetti, try another type of long noodle in this recipe, such as linguini or fettuccini. If you prefer fresh mussels over clams, use an equal amount of them in this recipe. If you do, cooking time and technique will be the same for the mussels as it for the clams.