Preheat your oven to 375°F (190°C). Lightly coat a 9-inch × 9-inch baking dish with cooking spray or line the bottom with parchment paper.

Remove any damaged outer leaves from the cabbage. Cut the cabbage into quarters, remove the tough core, and shred it finely.

Peel and grate the carrots. Finely dice the onion and mince the garlic.

Heat 1 tablespoon olive oil in a large skillet over medium heat. Add the diced onion and cook for approximately 3–4 minutes, stirring occasionally, until it begins to soften. Add the minced garlic and cook for another 30–60 seconds.

Add the shredded cabbage to the skillet. Add the salt, black pepper, oregano, parsley, paprika, and onion powder. Cook for approximately 6–8 minutes, stirring frequently, until the cabbage begins to soften.

Stir the grated carrots into the cabbage mixture. Continue cooking for approximately 3–4 minutes.

Remove the skillet from the heat and allow the vegetable mixture to cool for approximately 5–10 minutes.

In a large mixing bowl, whisk together the 4 eggs, Greek yogurt, mozzarella, Parmesan, Italian seasoning, salt, and black pepper.

Add the slightly cooled cabbage and carrot mixture to the egg mixture. Use a spatula to gently fold everything together until the vegetables are evenly coated.

Pour the mixture into the prepared baking dish. Spread it evenly with a spatula and gently press it into the corners. If using the optional mozzarella topping, sprinkle it evenly over the surface.

Place the baking dish in the preheated oven. Bake for approximately 30–40 minutes.

Insert a knife or toothpick into the center. It should come out mostly clean without a large amount of liquid egg mixture.

Remove the casserole from the oven and allow it to rest for 10 minutes before slicing.

Sprinkle the finished casserole with fresh parsley.

Slice the casserole into 6 portions and serve warm.