Heat the oil in a wide pot over medium heat. Add the onion and cook, stirring regularly, for 8-10 minutes until softened. Season with salt and pepper.

Add the chopped sun-dried tomatoes and 1 teaspoon tomato oil from the jar. Cook 3-4 minutes more.

Melt the butter into the onions and tomatoes. Once frothy, add the oregano and crushed red pepper. Cook 1 minute. Season with salt and pepper.

Pour in the water or stock and bring to a boil. Reduce heat to medium-low and hard simmer until thickened, about 15 minutes. If the sauce reduces too quickly, reduce heat to low and add a splash or two more of water. Taste and season to your preferences.

Bring a large pot of salted water to a boil. Add the pasta and cook until al dente. Scoop out 1/3 cup of the pasta cooking water and set it aside. Drain the pasta.

If using the truffle cream, add it to the reserved hot pasta cooking water and stir to temper it.

Add the mascarpone or heavy cream to the pot of sun-dried tomato sauce and bring to a boil. Reduce heat to medium and add the reserved pasta cooking water with truffle cream. Let the sauce bubble for 5 minutes until thickened. Taste and season.

Add the pasta and cook for 1-2 minutes more until completely coated with the sauce. Turn off the heat.

Divide the pasta between shallow bowls. Garnish with parsley. Enjoy!