Bring a large pot of lightly salted water to a boil.
Meanwhile, lightly mist a small nonstick skillet with olive oil spray. Set over medium heat. Add the onion and garlic. Cook, stirring occasionally, for about 4 minutes, or until almost tender. (Do not brown.) Add the clams. Increase the heat to medium high. Cook for 2 to 3 minutes, or until the excess liquid is completely evaporated. Reduce the heat to low. Add the tomatoes, oregano, and oil. Season with red-pepper flakes.
When the water boils, add the pasta to the pot. Stir. Cook, stirring occasionally, for 3 minutes, or until al dente. Drain and add to the skillet mixture. Toss to combine. Transfer to a serving bowl. Sprinkle with the cheese. Serve immediately.
Source: Devin Alexander from the Biggest Loser Cookbook