Preheat your oven to 180°C (350°F).

Cook the grikiai, rice, quinoa, and pasta separately according to package instructions. Drain well.

While the grains and pasta cook, heat a little oil or butter in a large pan over medium-high heat. Add the diced chicken and cook until browned and cooked through, about 5-7 minutes. Season with salt and pepper.

If using, add the chopped onion and garlic to the pan and cook until softened, about 3-5 minutes.

Add the broccoli florets to the pan with the chicken and cook for 3-4 minutes until slightly tender-crisp.

In the same pan, combine the cooked grikiai, rice, quinoa, and pasta with the chicken and broccoli mixture.

If using, pour in the milk or cream, add the grated hard cheese, and stir to create a light sauce coating the mixture. Add nutmeg if using.

Transfer the entire mixture into an oven-safe baking dish. Top evenly with the torn or diced mozzarella.

Bake for 15-20 minutes, or until the cheese is melted, bubbly, and golden brown on top.

Let it rest for a few minutes before serving. Garnish with fresh herbs if using.