Soak the corn husks in a bowl of hot water, using a plate to keep them submerged, until pliable, 1 hour.
Meanwhile, make the filling: Bring the bouillon powder and 4 cups water to a simmer in a medium pot over medium heat. Add the chicken and simmer until cooked through, 12 to 15 minutes. Remove the chicken and let cool; cut into small pieces. Reserve the broth.
Puree the cilantro and 1 1/4 cups of the reserved broth in a food processor until smooth (save the remaining broth for another use). Transfer to a medium pot. Add the garlic, cumin and salsa and bring to a simmer over medium heat; cook until slightly reduced, about 12 minutes. Stir in the chicken and season with salt. Remove from the heat and let cool.
Make the dough: Soak the ancho chile in hot water until soft, about 15 minutes. Drain the chile, then mince to make a paste. Combine the chile paste, masa harina, lard, 2 2/3 cups warm water and 2 teaspoons salt
in a bowl. Mix with your hands (or use a mixer with the paddle attachment) 10 to 15 minutes, or until a marble-size ball of dough floats in water.
Drain the husks and pat dry. Starting 1/2 inch from the wide end, spread about 3 tablespoons of the dough down a husk, leaving a 1-inch border on the sides. Spoon about 2 tablespoons of the chicken filling down the center of the dough, then fold in the sides of the husk, wrapping the dough around the filling. Fold up the narrow end of the husk. Repeat with the remaining husks, dough and filling.
Set a steamer basket in a large pot filled with 1 to 2 inches of water. Arrange the tamales standing up in the steamer, folded-side down. Bring the water to a boil over medium-high heat, then cover and steam until the tamales pull away from the husks, about 1 hour. Remove from the steamer and let cool slightly before unwrapping.