My tortoises would never eat the LS diet. Have you gotten yours to eat it? If so, congratulations.
If not, try the regular Mazuri. Most tortoises devour it ravenously. Soften it in water for a few minutes, then crumble it up over any food items you want the tortoise to try. Gradually you can reduce the amount of Mazuri and increase the volume of other items as the tortoise gets used to eating the new foods you offer it.
If you can find plantain, you can probably also find dandelion (flowers and greens are edible).
I feed my Russians Mazuri or Zoo-med twice a week, a couple of tablespoons, softened with water... if I'm trying to introduce a new food, I'll add more water and use the resulting slurry as a dressing over the new food.