Fry the chopped onions and pressed garlic in preheated oil. When soft, add the tomatoes and broth.
Season the sauce with salt, black pepper and oregano. Preheat the oven to 356°F (180 °C).
Pour the orzo in an oven dish and pour the tomato sauce in.
Bake the dish for a little more than half an hour, sprinkle it with cheese or gouda during the last 10 minutes.