Make the sauce: Place cashews in a small pot, cover with water, and bring to a boil. Simmer for 15 minutes, then drain and rinse well. Blend with fresh water and salt until smooth and creamy. Set aside.
Press the tofu: Remove tofu from its container and press to remove excess moisture. A tofu press works best, but stacking paper towels and a heavy skillet works too.
Sauté the veggies: Warm olive oil in a large skillet over medium heat. Add mushrooms, bell pepper, spinach, onion, or any other veggies. Cook until softened.
Add the tofu: Crumble the tofu into the skillet and stir to combine. Cook for about 5 minutes. Season with nutritional yeast, garlic powder, paprika, turmeric, salt, and pepper. Taste and adjust seasoning if needed.
Combine with cashew sauce: Pour the cashew sauce into the skillet and stir to combine. Add frozen shredded hash browns and mix everything together.
Transfer to baking dish: Coat a 9x13-inch casserole dish with cooking spray. Spread the hash brown mixture in an even layer and top with shredded vegan cheese. Preheat oven to 350°F. If making ahead, cover with plastic wrap and refrigerate until ready to bake.
Bake to perfection: Bake for 30 minutes, until the edges are golden brown and crispy. Let cool for 10 minutes before slicing and serving.
Notes
Make ahead: Prepare the casserole up to the baking step. Cover tightly with plastic wrap or foil and refrigerate for up to 2 days. When ready to bake, let it sit at room temperature while the oven preheats.Store leftovers: Let the casserole cool completely, then transfer leftovers to an airtight container. Store in the fridge for up to 4 days. Reheat in the microwave until warmed through.Freeze: Assemble the casserole in a freezer-safe dish but don’t bake it. Wrap tightly with plastic wrap and foil. Freeze for 2-3 months. Thaw overnight in the fridge before baking as directed. Baked leftovers can also be frozen in individual portions and reheated as needed.