In a large pot of salted boiling water, cook the pasta according to package instructions until al dente. Drain and set aside, reserving a small cup of pasta water.

In a large skillet, heat the olive oil over medium heat. Add the diced onion and sauté for 3-4 minutes until translucent. Stir in the minced garlic and cook for an additional minute.

Add the sliced mushrooms to the skillet and cook until they are browned and tender, about 5-7 minutes.

Pour in the vegetable broth and bring to a simmer. Stir in the heavy cream, dried thyme, and dried oregano. Allow the sauce to simmer for 5-10 minutes, thickening slightly. Season with salt and pepper to taste.

Add the cooked pasta to the skillet with the mushroom cream sauce. Toss to combine, adding reserved pasta water a little at a time if the sauce is too thick.

Remove from heat and stir in grated Parmesan cheese if using. Garnish with fresh parsley before serving.