To prepare the filling, first heat a few tablespoons cooking oil in a large Dutch over medium-high to high heat. Pat the pork dry and season generously with salt and pepper. When the oil is shimmering, add the pork (cut in half and working in two batches if necessary to fit in your pan) and sear until crisp and golden brown, about 3 to 5 minutes per side. Remove the meat and set aside.

Lower the heat to medium. Add the onions and cook until softened, about 5 minutes. Add the garlic and spices and cook for another 30 to 60 seconds.

Return the pork to the skillet and add enough stock to come approximately three quarters up the sides of the meat. Bring the liquid to a boil, cover, and reduce heat to medium-low. Simmer until the meat is very tender and falls apart easily when pulled with a fork, 2 to 2 1/2 hours. Turn off heat and set aside until cool enough to handle. Remove and discard any skin and large chunks of fat. Shred the remaining meat and transfer to a large bowl.

Strain the cooking liquid, discarding the solids. Ladle enough remaining liquid over the meat to make it juicy but not runny. Taste and adjust seasoning. (If making the filling in advance I like to add a drizzle of canola oil to the meat after bringing to room temperature, as fat in the filling ensures the cooked tamale stays rich and moist.)

To prepare the dried corn husks for the tamales, fill a very large bowl — I use my large tamale pot — or kitchen sink with hot water. Add the husks, placing a heavy pot or weight on them to keep submerged. Soak until they are soft and pliable, a minimum of one hour; alternately you can soak them in cool water overnight. Rinse the husks to remove any dust and hold them in a large mixing bowl covered with a clean, damp towel. (Husks can be re-soaked if necessary.)

To make the dough, place the butter in the bowl of a stand mixer fitted with a paddle attachment and cream on medium-high speed for 2 minutes, until light and fluffy. Reduce speed to low and add the baking powder and salt. Start adding the masa harina to the butter mixture, adding a few glugs of stock (about 1/4 cup) after every cup or so of masa. Stop the mixer occasionally to feel the texture of the dough — it should feel light, airy, and slightly sticky, almost like grainy mashed potatoes; adjust ingredients as necessary until this texture is reached. Turn the mixer to high and continue beating for 1 to 2 minutes, then test the dough for doneness. Drop a couple pea-sized balls into a cup of cold tap water. If it is ready the balls will float to the top. If they sink, add a splash of stock and continue beating to incorporate more air into the mixture. Test dough again before moving forward. (The dough can be refrigerated at this point. Return to stand mixer and beat for a few minutes before using.)

To assemble the tamales, carefully remove a single corn husk from the water and pat quite dry. Flatten the husk, rough side down, on a clean work surface so that it runs horizontal to the counter. Using a spring-form ice cream scoop or measuring cup (for consistency when measuring), drop the dough onto the lower portion of the wide end of the husk. Use your fingers or an offset spatula to press the dough into an even rectangle about a 1/4-inch thick and leaving a 1/2-inch border at the wide edge. (If the dough feels too moist, dip your fingers in a bowl of masa to prevent sticking.)

Spoon 1 to 2 tablespoons of the meat mixture in a fairly thin line down the center of the dough. Carefully roll the husk away from yourself so the bottom edge of dough meets the top edge of dough. Gently press the seam to seal, using a pinch of additional dough as "glue" if necessary. (Any gaps in the seam can allow filling, i.e. moisture, to escape while steaming.) Once sealed, roll the husk sushi-style to form a tight cylinder. Tuck the thin bottom end under and tie the folded end with kitchen twine if desired. Stack the tamales on a sheet pan and repeat until all dough and filling is used. (If multiple people are making tamales it can be more efficient to work assembly line-style, i.e. one person dries husk, one spreads dough, one fills, one ties, and so on.)

To steam the tamales, fill a large tamale pot or stock pot fitted with a steamer basket with enough water to reach just below the insert and bring to a boil. Reduce heat to medium-low heat so that the water is gently simmering but not boiling. Cover the holes in the insert with a few extra corn husks to help concentrate the heat. Arrange the tamales upright in the pot (like skyscrapers) with the open end pointing up, folded side towards the water. Continue arranging until the tamales are firmly packed but not overcrowding the pot, allowing some room for the dough to expand. Cover the tamales with additional husks and place a lid on the pot.

Steam the tamales, monitoring the heat to ensure the water simmering and the pot has not gone dry. (You can place a few pennies in the water of the steamer basket — if you start hearing them rattle, the water is getting low.) Cook the tamales for 1 to 1 1/2 hours; to check for doneness, remove a tamale and set aside for 5 to 10 minutes to rest. If the dough firms up and the husk easily peels away from the masa it is done. For firmer tamales, remove from the pot, cover with a dish towel, and rest for 5 to 10 minutes before serving. For softer tamales, take the pot off the heat. Remove the lid and discard the extra corn husks draped over the tamales and covering the holes in the insert (just stick tongs down towards the bottom to pull them out). Let tamales rest in the pot for 5 to 10 minutes before removing to serve. After removing tamales, reserve a few cups of cooking liquid and set aside.

Serve tamales warm in their husks, discarding husks before eating. For moister tamales, drizzle a few teaspoons of reserved cooking liquid over the top. Serve with Mexican creme, salsa verde, and hot sauce.