Start making making the Green Sauce. Combine lettuce, mayonnaise, lime juice, cilantro, peppers, garlic, and salt in a blender. Blend until smooth. Put into a serving dish.
Next, we fry the yucca. Peel the yucca with a knife and throw away the hard skin. Cut the flesh into 1/2 inch thin strips about 4 inches long. Heat a large iron skillet or nonstick frying pan to medium high heat with about half your oil. I like grape seed oil because it gives a nice crispness to the yucca and it's healthy. Reserve the remaining oil for the 2nd half of your yucca. Organize the yucca in the frying pan into a single layer. fry half the yucca until light golden brown and then flip it over to fry on the other side. Remove when it's golden brown on both sides and place onto a paper towel to drain. Cook the 2nd batch the same way.
Serve the yucca on a plate, and give each person a small bowl or cup of the green sauce for them to dip their yucca into.