Drain the clams and reserve the juice. Or measure out 1 cup of the clam-steaming liquid and set aside.

In a large saucepan, heat the olive oil and butter. Add the garlic and simmer for about 3 minutes, just until the garlic begins to color; do not let the garlic turn brown or the sauce will taste bitter. Add the parsley, oregano, basil, salt, pepper, tomatoes, tomato sauce, and clam juice. Simmer for 45 minutes. Add the clams and cook just enough to heat through.

Meanwhile, cook the pasta in plenty of boiling salted water according to the package directions. Drain. Place the pasta in individual serving bowls and pour the sauce on top.