Place the yuca in a large saucepan and cover with cold water. Bring up to a boil, then reduce the heat so that the water is simmering and cook for 20 to 25 minutes, or until fork-tender. Check individual pieces for doneness, some pieces may cook faster than others. Drain in a colander and, when cool enough to handle, cut into quarters lengthwise and remove and discard the fibrous cores.

In a very large skillet, combine the butter and olive oil over medium heat. Add the yuca pieces and sprinkle with 1 teaspoon of the salt. Cook the pieces on one side for about 10 minutes, stirring frequently, until brown. Turn the yuca pieces over with tongs and sprinkle with the remaining teaspoon salt. Cook for 10 to 15 minutes more, until the pieces are deep golden brown on all sides. With a slotted spoon, transfer to a large heated platter. Sprinkle with the chopped parsley and the lime juice and serve, accompanied by wedges of lime.

Note: Yuca, which is also called cassava, is available fresh and frozen in Hispanic markets. Check that there are no hairline cracks in the bark-like brown skin when purchasing fresh yuca. Yuca should be kept in a cool place outside the refrigerator. If you use some of it, peel the rest and store in the refrigerator in water to cover for I day, or freeze, well wrapped, for up to 3 months. To peel, first scrub and then cut it in half crosswise. Quarter each section lengthwise, then peel away the outside skin with a sharp knife. Rinse before cooking.