1. Preheat the oven. Heat the oil in a heavy-bottomed pan and sauté the onion until translucent. Stir in the mushrooms and green pepper and continue to fry until soft and cooked (fry the mushrooms separately, if you prefer them browner). Remove from the heat, allow to cool slightly, then mix in the ham and sausages.
2. Spoon the mixture into a greased tart pan. Arrange the egg halves between the filling mixture and sprinkle the parsley over.