In a large saucepan, heat the vegetable oil. When the oil is hot, add the onions, peppers, and celery. Season with salt and cayenne. Saute the vegetables for about 5 minutes, or until the vegetables are wilted. Add the sausage and saute for 2 minutes. Add the bay leaves, tomatoes, and garlic. Saute for 2 minutes. Stir in the rice and saute for 2 minutes. Add the stock. Season with salt and cayenne. Bring the liquid up to a boil and reduce to a simmer. Cook the jambalaya for 25 to 30 minutes, covered, or until the rice is tender and the liquid has been absorbed. Stir in the crawfish tails and green onions and re-season, if necessary.