Boil noodles in well-salted water until al dente. Drain and set aside; reserve 1/2 cup cooking water.
Warm olive oil and butter in a large skillet over medium heat until melted and shimmering.
Soften the onion, stirring often, until translucent, about 4 minutes.
Add mushrooms and cook, stirring occasionally, until browned and their liquid evaporates, 7–9 minutes.
Stir in garlic, paprika, and thyme. Cook until fragrant, about 30 seconds.
Sprinkle flour over the mushrooms. Stir to coat and cook 1 minute to remove the raw taste.
Pour in the wine and scrape the pan. Simmer until nearly absorbed, 1–2 minutes.
Whisk in the broth, Dijon, and Worcestershire. Simmer gently until the sauce thickens and turns silky, 4–5 minutes.
Lower heat. Stir in sour cream and lemon juice until smooth. Season with salt and pepper to taste.
Toss noodles with the sauce, loosening with a splash of reserved pasta water if needed. Finish with parsley and serve.