Stir the lard and egg into the warm mashed potatoes until thoroughly incorporated. Combine crushed pork rinds with the flour, and stir into potatoes. Season to taste with salt if necessary.
Form into golf ball-sized pieces on a lightly-floured surface, then press to form into disks about 3/4-inch thick.
Heat the canola oil in a large skillet over medium heat. Fry the chapaleles on both sides until crisped and golden brown, 4 to 5 minutes per side. Alternatively, they may be baked in a 375 degrees F (190 degrees C) oven until golden brown, about 25 minutes.
