Prepare the Vegetables: Finely shred the cabbage, grate the carrots, and finely chop the onion and parsley. Set aside.
Sauté the Vegetables: Heat olive oil in a skillet, add onion and sauté until soft. Add cabbage and carrots, cook until tender. Season with salt and pepper, then remove from heat.
Prepare the Egg Batter: In a bowl, whisk eggs until frothy. Add flour, milk, olive oil, baking powder, salt, black pepper, and oregano. Whisk until smooth.
Combine the Vegetables and Batter: Fold the sautéed vegetables into the egg batter until evenly distributed.
Add the Mozzarella Cheese: Fold in shredded mozzarella, reserving some for topping.
Cook the Frittata: Preheat oven to 180°C (350°F). Grease a skillet, pour in the mixture, sprinkle remaining mozzarella on top, and bake for 20-25 minutes until set and golden.
Garnish and Serve: Let cool slightly, garnish with parsley, and serve warm.
