1. Preparing the Achiote Rub:
2. Note, if using prepared achiote paste instead of achiote seeds, skip the soaking and crushing step. Simply mash the paste with the orange juice and vinegar and then transfer the mixture to a blender.
3. Mix the achiote seeds with the orange juice and vinegar and soak for 1 hour to soften them.
4. Using a molcajete, or Mortar and pestle, crush the achiote seeds with a little of the soaking liquid.
5. Transfer the seeds and soaking liquid to a blender and add the remaining rub ingredients; blend to a paste.
6. Reserve 2 tablespoons of the paste for cooking with the tomatoes.
7. Rub the pork cubes with the remaining achiote rub and set aside.
8. Heat Oil in heavy skillet over medium heat. Add tomatoes, Onions and the reserved 2 tablespoons of achiote rub. Fry for about 3 minutes and set aside.
9. Cooking the Pork:.
10. Preheat oven to 350 degrees. have a large heavy dutch oven ready.
11. Using tongs, carefully sear the banana leaf over an open flame until flexible.
12. Line the dutch oven with the banana leaf and arrange the pork cubes on the leaf.
13. Cover the pork with Tomato mixture, folding the banana leaf over the top.
14. Cover and cook in preheated oven for 2 to 2/12 hours basting occasionally with juices from bottom of the pot. Remove from the oven and transfer to a serving platter.
15. Garnish with Cebollas Rojas en Escabeche (mexican pickled vegetables) and serve with white rice. Serve 6.