Wash the fresh spinach carefully or defrost thoroughly if using frozen spinach.

In a large kettle or pan, heat olive oil over medium heat.

Sauté the chopped onion and minced garlic in the olive oil for a few minutes until the onion becomes transparent.

Add the spinach to the pan with the onion and garlic.

Cover the pan tightly and cook for 2 to 3 minutes, allowing the spinach to wilt.

Stir the spinach into the onion and garlic mixture.

Preheat oven to 375°F (190°C).

Grease a medium-sized baking dish with butter.

Allow the spinach mixture to cool slightly.

In a separate bowl, whisk the 2 beaten eggs.

Stir the beaten eggs and 1/2 cup of Parmesan cheese into the slightly cooled spinach mixture.

Season the mixture with salt and pepper to taste.

Pour the spinach mixture into the greased baking dish.

Sprinkle the remaining Parmesan cheese evenly over the top of the spinach.

Dot the top of the spinach with small pieces of butter.

Bake in the preheated oven for 10 to 15 minutes, or until the top is golden brown and the dish is heated through.

Serve hot with rice on the side.