A day in advance, trim fat from meat. If not already cut into 4 strips, cut meat into 4 strips and place into a large pot.
Add broth or water, onion, garlic, bay leaves, 1 tablespoon salt, peppercorns, 1/2 teaspoon oregano and 1/2 teaspoon cumin. Bring to a boil.
Reduce heat, cover and simmer 1 hour. Drain meat, reserving about 5 cups of the broth for the tamale dough.
With 2 forks, shred the meat and mix in 4 tablespoons flour, 1 tablespoon salt,.
1 tablespoon ground black pepper, 1 tablespoon dried oregano and 3 tablespoons ground cumin. If too dry, add a little broth to make it like a paste.
Refrigerate the meat mixture and the reserved broth overnight. If you like it on the tangy side, add some chopped chilis to the meat mixture.
You will only use about half of the meat filling mixture. The other half you can freeze for the next time you make tamales. So, the next time, you will only have to make the dough.
The next day, soak the corn husks in hot water 1 hour to soften. Also soak a few additional husks to cover tamales. Rinse and pat dry with paper towels.
Prepare the dough by mixing all the dough ingredients, except the corn husks, with warm pork broth. You will need to make 2 batches of the dough. Hold each corn husk with point towards you. Place a rounded tablespoonful of dough at large end of husk. Spread with fingers. Place 2 or 3 tablespoons of pork filling on dough. Top with another tablespoon of dough and spread to cover filling.
Fold sides of husk over the tamale. Fold pointed end of corn husk under the seam on outside. Stand tamales on folded ends on a steaming rack over water in a large pot.
Cover with additional layers of husks. Bring water to a boil. Reduce heat, cover and steam 1 hour, or until dough pulls away easily from husk. Makes about 32 tamales.