To prepare the pork:

Cut the meat of the pork shoulder into smaller pieces, in order to reduce cooking time.

Place all of the meat and any bones into an 8 qt. (8 lt) stock pot. Cover with water, and add the onion, garlic, bay leaves and salt, and bring to a boil.

When it is well cooked (about 45 minutes of cooking time), remove the meat from the broth. Reserve the broth for later use. Remove any meat from the bones, and discard the bones. Mince the cooked pork, chopping by hand, or using a meat grinder. (A 5 lb (2.2kg) pork shoulder should yield about 8 cups of chopped meat.)

To prepare the seasoning for the meat filling:

Fill a 6 qt stock pot (6lt) half way full with water. Bring the water to a boil and add the chiles. Boil the chiles until tender, about 15 minutes. Remove and discard the stems and seeds, and add the chiles to the container of a blender. Add 1 cup of the pork broth and garlic, and puree well (add more broth if necessary to facilitate blending.) Strain puree through a wire strainer to extract any remaining seeds and discard the seeds.

In a skillet, heat ½ lb of pork lard (250g) over low heat. When melted, add the garlic, pepper,  and salt, and sauté for 10 seconds. Add the puree, and sauté for 2 minutes. Add the chopped pork, combining well. Adjust the seasonings as desired. Simmer for 10 minutes, and then remove from heat. Set aside. (You may elect to prepare the meat a day in advance. Once cooled, you can also freeze the meat for a later tamal making date.)

Prepare the masa as directed in the following recipe.

To assemble the tamales: Dry off some of the corn shucks, and place a few within reach. To make a proper tamal, the corn shuck bottom edge should be around 6 inches (15cm) wide. Discard those that are too narrow, and tear bits off of the ones that are too wide.

Take a corn shuck, and spread the bottom 2/3 of the leaf with 2-3 (30g-45g) tablespoons of masa. Leave a 1-½ inches (2cm-4cm)wide area along one edge free of masa. Spread the masa thinly. Place line of about 2 tablespoons (30g) of the filling, following the direction of the corn shuck veins, on the spread masa, towards the center of the prepared shuck. Fold the edge of the prepared shuck over the filling, and then roll up towards the edge of the shuck with no masa. Fold down the top part of the shuck. Continue until all the tamales have been formed.

You will need a two piece steamer pot with a lid in order to cook your tamales. Place tamales in the basket of the steamer. Boil water in the bottom of the steamer. As a top layer, cover the tamales with extra corn shucks, then with a sheet of aluminum foil. Secure the lid of the steamer, using foil around the edges of the lid to prevent the escape of steam. Place the steamer over the boiling water. Steam the tamales for about 25 – 40 minutes, until the masa is firm and no longer appears opaque.