Combine the ground meat, bread crumbs, 1 egg, 1/4 cup of each cheese, oregano, salt and pepper in a bowl. Mix thoroughly, then form the mixture into 3/4-inch to 1 1/2-inch balls. You should have 20 to 30 meatballs, depending on how large you form them.

In large skillet, heat 2 tablespoons oil over medium high heat. Add the meatballs in batches, and cook, turning, until browned all over, 3 to 5 minutes. (If they are still a bit pink in the middle, don't worry, they will continue to cook in the broth.) Set them aside on paper towels to absorb excess oil.

In a 4 to 6 quart soup pot, heat the remaining 1 tablespoon oil over medium high heat. Add the onion and garlic and sauté until onions are tender and garlic is soft, but not browned, about 5 minutes. Add the stock and bring to a boil. Add the greens, reduce the heat to low, cover, and simmer for 10 minutes. Add the meatballs and cook another 5 minutes.

Meanwhile, combine remaining 2 eggs and remaining cheeses in small bowl and stir with a fork to blend. Slow pour the egg mixture into hot soup, stirring constantly. Cover and simmer just until egg bits are set, about 1 minute. Season to taste with salt and black pepper, maybe even a squirt of lemon juice, and serve immediately in a low bowl if possible so the meatballs are visible.

To re-heat, simmer gently over low heat.