Preheat your oven to 180°C (356°F).
Wash the spinach thoroughly and chop it roughly.
In a pan, heat some olive oil over medium heat. Add the chopped red onion and minced garlic. Saute until they are soft and fragrant.
Add the chopped spinach to the pan. Cook until the spinach wilts and any excess water evaporates. Season with salt, pepper, and optional chili pepper to taste. Remove from heat and set aside to cool slightly.
In a mixing bowl, beat the eggs. Add the milk and flour gradually, whisking until you have a smooth batter.
Crumble the Greek Feta cheese and add it to the batter. Mix well.
Grease a baking dish with olive oil. Spread the cooked spinach mixture evenly on the bottom of the dish.
Pour the egg and Feta cheese batter over the spinach layer, ensuring it covers the spinach evenly.
Sprinkle grated mozzarella cheese on top of the casserole.
Bake in the preheated oven for about 20 minutes or until the top is golden and the casserole is set.
Once done, remove from the oven and let it cool slightly. Garnish with fresh parsley before serving.
Enjoy Grandma’s amazing spinach casserole! It’s sure to impress everyone at the table.
Bon appetit!