Bring a large pot of water to a boil over high heat.
In a large saucepan over medium heat, melt the butter with the olive oil. Add the onions, garlic and thyme and sauté until softened, about 3 minutes.
Place the tomato sauce, roasted peppers, chicken or vegetable broth in the blender and blend until smooth.
Add the tomato mixture to the sauce pan and cook, stirring frequently, about 5 minutes. Season with salt and pepper.
Add the heavy cream, oregano, parmesan cheese and cook for about 5 minutes more. Stir and add red pepper flakes.
Meanwhile, add 2 tbs. salt and the pasta to the boiling water. Cook, stirring occasionally to prevent sticking, until al dente, according to the package instructions.
Drain the pasta and add to the sauce. Warm briefly over low heat to blend the flavors and serve.