Preheat the Oven: Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish with olive oil.

Prepare the Hash Browns: Spread the thawed hash browns evenly in the prepared baking dish.

Sauté the Vegetables: In a large skillet, heat the olive oil over medium heat. Add the diced onions and garlic, and sauté until softened. Add the bell peppers, mushrooms, and cherry tomatoes. Cook until the vegetables are tender and any excess moisture has evaporated. Stir in the chopped spinach and cook for another 2 minutes until wilted.

Prepare the Tofu Mixture: In a blender or food processor, combine the crumbled tofu, plant-based milk, nutritional yeast, chickpea flour, turmeric, smoked paprika, dried oregano, salt, and pepper. Blend until smooth.

Combine Everything: Pour the sautéed vegetables over the hash browns in the baking dish. Spread them out evenly. Pour the tofu mixture over the vegetables and hash browns, ensuring everything is well coated and distributed evenly.

Bake the Casserole: Place the baking dish in the preheated oven and bake for 45-50 minutes, or until the top is golden brown and the casserole is set.

Cool and Serve: Remove from the oven and let the casserole cool for 10 minutes before slicing and serving.