Combine yuca, green plantains, yautia, and milk in a blender; puree into a thick paste the consistency of oatmeal.
Combine lard and achiote seeds in a saucepan over medium-low heat; heat until lard is melted, and reddish in color, about 5 minutes. Strain out achiote seeds. Mix half of the lard into the yuca paste.
Heat olive oil in a large pot over medium heat. Add onion and green bell pepper; cook and stir until tender, about 5 minutes. Add pork, ham, garbanzo beans, tomato sauce, olives, capers, orange juice, cilantro, oregano, salt, and garlic; cook and stir until pork is no longer pink in the center, 8 to 10 minutes. Remove from heat.
Mix 2/3 of the remaining lard into the pork mixture.
Smear each plantain leaf with a small amount of remaining lard. Place a large spoonful of the yuca paste in the center of each one; top with a scoop of the pork mixture. Fold up the sides of each leaf to enclose the filling and create a rectangular pastel.
Stack 2 pasteles and tie them together with kitchen string. Repeat with remaining pasteles.
Bring a large pot of water to a boil. Add pasteles. Cook until filling is tender, about 1 hour. Unwrap pasteles before serving.