Discard any clams with cracked or open shells. Rinse in cold water to remove grit.
Drizzle olive oil in saucepan. Over medium heat sauté the onions until soft, about five minutes. Add garlic. After about one minute add parsley, Italian seasoning and pepper flakes. Stir until aromatic, about two minutes.
Add the clams and white wine. When the clams open, remove from heat and cover.
Plate dish by placing cooked spaghetti in the center edged with clams. Drizzle clam broth and yummy bits over the top. Garnish with tomato. Serve immediately.
Note: Do not toss excess liquid; it makes an excellent broth for soups.