Method 1: Heat the cooking oil in a wok. Add the pork and sausage and stir fry for about 30 seconds or just until heated through. Add the shrimps and peas and cook until the shrimps change color. Add the rice. Season with salt and pepper; pour in the oyster sauce, if using. Stir gently but thoroughly and cook until the rice is hot. Pour in the beaten eggs. When the eggs are partially set, sit and continue cooking until the eggs are cooked through. Drizzle with sesame seed oil and stir before serving.