Dice the sausage, zucchini and potato on a cutting board. If desired, beat eggs in a small bowl with a fork and set aside. Heat oil at high temperature in a medium sized pan for about 2-3 minutes. Add the zucchini and potato to the pan, saut? and then add the sausage with the lard. After the vegetables and sausage are well fried, pour in the eggs and stir. Fry eggs for a couple of minutes until firm.