Heat the oil in a large skillet over medium heat. Add the onion and garlic and cook until softened, about 5 minutes. Add the bell pepper and mushrooms and cook for an additional 5 minutes.
Sprinkle the flour over the vegetables and stir to combine. Pour in the white wine or broth and cook for 1 minute.
Add the vegetable broth, tomato paste, thyme, and black pepper. Bring to a simmer and cook until thickened, about 10 minutes.
Stir in the cooked noodles or pasta of choice. Simmer for 2-3 minutes until heated through.