Wrap each yucca in 3 layers of heavy-duty aluminum foil. Place on hot coals. Roast 1 hour or until tender, turning after 30 minutes. Unwrap.
Cook yucca over an open fire, using long-handled tongs, until skin is blackened. Cool. Peel and cut yucca into 1-inch cubes.
Melt butter in a large skillet; add chicken broth and seasonings. Bring mixture to a boil; add yucca. Reduce heat and simmer for 10 to 15 minutes.
Note: To prepare indoors, wrap yucca in heavy-duty aluminum foil. Bake at 375° for 1 hour or until tender. Using long-handled tongs or a long-handled fork, hold yucca above the flame of the gas cooktop, turning it until the skin blakens. Cools. Peels and cut into 1-inch cubes. Proceed as directed.