Bring a large pot of salted water to boil and cook pasta according to package directions. Drain and set aside.
In the same pot, heat olive oil over medium heat. Add onion and cook until softened.
Stir in garlic and mushrooms. Cook until mushrooms release their moisture and begin to brown.
Add soy sauce, smoked paprika, and flour. Stir until flour coats the mushrooms.
Slowly whisk in vegetable broth, followed by plant-based milk. Stir until smooth.
Add Worcestershire sauce and Dijon mustard. Let simmer for 8-10 minutes until sauce thickens.
Season with salt and pepper. Return pasta to the pot and toss to coat in sauce.
Garnish with fresh parsley before serving.