Preheat and prep: Heat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish. Put a large pot of salted water on to boil for the pasta.

Cook the pasta: Boil until just shy of al dente (about 1–2 minutes less than package directions). Drain and set aside. Toss with a little olive oil to prevent sticking.

Sauté the aromatics: In a large skillet, warm 2 tablespoons vegan butter or oil over medium heat. Add the onion with a pinch of salt and cook 6–8 minutes until soft and lightly golden. Stir in the garlic and cook 30 seconds.

Brown the mushrooms: Add the mushrooms and the remaining tablespoon of butter or oil. Cook, stirring occasionally, until they release their moisture and start to brown, 8–10 minutes. Don’t rush this step—browning builds flavor.

Season the base: Stir in Dijon, smoked paprika, thyme, and soy sauce or tamari. Cook 1 minute to bloom the flavors.

Add the broth: Pour in the vegetable broth and bring to a gentle simmer.

Make the cashew cream: Blend soaked cashews with 1 cup water until completely smooth. Add nutritional yeast if using. In a small bowl, whisk cornstarch with 2 tablespoons water to make a slurry.

Thicken the sauce: Stir the cashew cream into the skillet. When it returns to a simmer, whisk in the cornstarch slurry. Cook 1–2 minutes until the sauce turns silky and coats a spoon. Add lemon juice. Taste and season with salt and plenty of black pepper.

Combine and assemble: In a large bowl, mix the cooked pasta with the mushroom sauce. Transfer to the baking dish. If you like a crunchy top, sprinkle with bread crumbs and a drizzle of olive oil.

Bake: Bake uncovered for 18–22 minutes, until bubbling at the edges and lightly golden on top.

Finish and serve: Let it rest 5–10 minutes to set. Sprinkle with chopped parsley and serve warm.