Cook the spaghetti according to package instructions in a large pot of salted boiling water until al dente. Drain and set aside.
In a large skillet, heat the olive oil over medium heat. Add the diced onion and sauté for about 3-4 minutes until softened.
Add the minced garlic and sliced mushrooms to the skillet. Cook for an additional 5-7 minutes, stirring occasionally, until the mushrooms are browned and tender.
Stir in the dried thyme and oregano, cooking for another minute until fragrant.
Pour in the heavy cream and vegetable broth, stirring to combine. Bring the mixture to a simmer and let it cook for about 5 minutes, allowing it to thicken slightly.
Add the cooked spaghetti to the skillet and toss to coat in the creamy sauce. Stir in the grated Parmesan cheese and season with salt and pepper to taste.
Serve immediately, garnished with fresh chopped parsley.