STEP 1: Set your oven to 350°F (175°C) and lightly grease a 9×13-inch baking dish. Heat the olive oil in a large pan over medium heat. Add the mushrooms with a small pinch of salt and cook for about 5–7 minutes, until they soften and start to brown.
STEP 2: Add the diced onion and cook for another 3–4 minutes, until it becomes soft and slightly translucent.
STEP 3: Stir in the spinach and cook just until it wilts. Remove the pan from the heat, then spread the cooked vegetables evenly in the prepared baking dish. Let them cool for a few minutes.
STEP 4: In a blender, combine the eggs, cottage cheese, dried parsley, garlic powder, the remaining salt, and black pepper. Blend until the mixture is smooth and creamy. Stir in the shredded cheese afterward.
STEP 5: Pour the egg mixture over the vegetables in the baking dish, spreading it out evenly.
STEP 6: Bake for 35–40 minutes, or until the center is fully set and the top has a light golden color. Allow it to cool slightly before cutting into portions.