Peel yuca using a vegetable peeler.
Place the yuca on a cutting board. Cut in half lengthwise, using a chef’s knife. Remove the fiberous “root” in the center of the yuca. Place each half, cut side down on cutting board, and cut in half crosswise. Now cut each section into “fries”, about 1/2- inch x 4 to 5 inches.
Fill a large saucepan about 1/3 full of water. Bring to a boil over high heat. Gently add the fries to the boiling water; boil for 4 to 5 minutes. Drain.
Spread the fries out to dry on a wire rack or baking sheet. Pat dry with a paper towel, or let air dry about 30 minutes.
Heat oil in a large skillet. Oil should be about 1/2-inch deep. When oil is hot, place some of the fries in the skillet and fry about 7 to 9 minutes, until beginning to brown on the edges. Remove from hot oil onto a paper towel lined plate. Sprinkle with garlic salt. Repeat frying batches until all are used. Serve hot.