Pre-heat oven to 350F (180 C), lightly butter a small 8 x 6 inch (20 x 15 cm) baking dish and sprinkle with 2 tablespoons of bead crumbs.
Chop the onion and fry in 1 1/2 tablespoons of olive oil until lightly golden, remove and place in a large bowl.
In a medium pot add peeled potatoes (whole), cover with water and boil until tender, remove from water with a slotted spoon. Either mash or pass through a potato ricer (which is what I did) into the bowl containing the cooked onion.
Clean and trim the green beans, cut into 1/4 inch (.6cm) size pieces and set aside. Once the potatoes are cooked and removed from the water add the chopped green beans and cook just until tender (they should still have a bite to them). Then drain well and place in the large bowl with the potato and onion.
In a small bowl add the eggs and beat with a fork, then add the parmesan cheese, oregano, salt and pepper, and combine. Then add to the large bowl and gently combine all the ingredients.
Spoon into the prepared baking dish, sprinkle with remaining 2 tablespoons of bread crumbs, dot with 1 tablespoon of butter and bake for approximately 20 -25 minutes, the last couple of minutes raise the heat to 400F (200C) and let brown lightly. Let sit 5 minutes before serving. Enjoy!