Place the yucca in a large 6-quart pot. Cover with 5 quarts cold water. Add the salt and bring to boil over high heat. Lower heat to medium and cook covered until it feels tender when pierced with a fork but still keeps its shape, about 30 minutes. Be careful not to overcook because yucca can turn into a gooey paste. Turn the heat to low and leave the yucca in the hot water until ready to serve.
For The Mojo Sauce: While the yucca cooks, prepare the mojo sauce. Heat the olive oil until fragrant in a medium frying pan over medium-high heat. Saute the onion rings until lightly golden. Add the garlic and the cumin and saute, stirring for a few seconds, until golden. Pour in the bitter orange juice. Season with salt and pepper, to taste. Very quickly, drain the yucca in a large colander and transfer to a decorative serving platter. Cover with the mojo sauce and serve piping hot.
In Cuba and the Hispanic Caribbean, yucca con mojo is served alongside rice and beans and roast pork