STEP - 1
Place the dry corn husks in a baking dish. Pour hot water over the husks to cover. Weigh the husks down so they are completely submerged and let soak for 2 hours, or until pliable.
STEP - 2
Add the tomatoes, onion, guajillos, pasillas, garlic, and 4 cups (960 ml) of water to a small pot. Cover, bring to a boil, and cook for 10 minutes, or until the vegetables have softened.
STEP - 3
Transfer the vegetables to a blender, Add salt and pepper to taste, the cumin, and about ½ cup (60 ml) of the cooking liquid. Blend until smooth. Set aside.
STEP - 4
Heat the canola oil in a large skillet over medium-high heat. Add the pork and season with salt and pepper. Fry the pork until well-browned and most of the fat has evaporated. Drain any excess fat, if necessary.
STEP - 5
Add the sauce to the pan with the pork, bring to a boil, cover, and let simmer until tender, about 1 hour. Remove from the heat and let cool.
STEP - 6
In a small bowl, combine the baking soda, baking powder, and 1 tablespoon water. Stir to dissolve, then set aside.
STEP - 7
Add the lard to a large bowl. With an electric hand mixer, whip the lard until light and fluffy, about 5 minutes.
STEP - 8
Add the masa and baking soda mixture and mix with your hands until smooth, about 5 minutes. It should be spreadable but still hold its shape.
STEP - 9
Drain the soaked corn husks.
STEP - 10
Place 1 husk on a clean surface and add 1-2 tablespoons of masa to the center of the husk. Spread with the back of the spoon to about ¼ inch (¾ cm) from the edges.
STEP - 11
Place 1 tablespoon of meat in the center. Roll the corn husk over the filling from left to right and fold the top down to create a little pocket. Set aside. Repeat with the remaining ingredients.
STEP - 12
Place the tamales, open ends up, in a steamer basket set over a large pot of boiling water. Cover with a clean kitchen towel and the lid. Let steam for 1 hour, then turn off the heat and let the tamales rest for 1 hour more.
STEP - 13
Unwrap the tamales and serve with salsa verde.