1. In a kettle, combine the yuca with enough cold water to cover it by 1 inch. Bring the water to a boil, and slowly simmer the yuca for 20 to 30 minutes or until it is tender.2. Preheat oven to 350°F.
Set oven to 400 degrees.
Wash and cut turnips in half. Rub with olive oil and wrap in aluminum foil. Peel sweet potatoes and rub with olive oil and cover with aluminum foil. Put both into the oven until easily pierced with a fork (about 45 minutes).