Begin by gathering all your ingredients to streamline the cooking process. Finely chop the onion, mince the garlic, and slice the mushrooms and seitan into uniform pieces.

In a large skillet, heat the olive oil over medium heat. Add the chopped onion and sauté for 5–7 minutes until translucent.

Stir in the minced garlic and cook for an additional 1–2 minutes until fragrant.

Increase the heat to medium-high and add the sliced mushrooms to the skillet. Cook for about 8-10 minutes, stirring, until browned.

Push the mushrooms to one side and add a splash of olive oil. Introduce the sliced seitan to the skillet and sauté for 3–4 minutes until browned.

Sprinkle the flour over the mushroom and seitan mixture, stir for 2 minutes to create a roux. Gradually add the vegetable broth while stirring.

Reduce heat to medium-low and stir in the dairy-free sour cream, Dijon mustard, soy sauce, smoked paprika, and thyme. Simmer for 5–7 minutes.

In a pot, boil salted water and cook the pasta according to package instructions until al dente, then drain.

Combine the noodles with the sauce or serve sauce over noodles. Garnish with fresh parsley and lemon wedges, if desired.