Place the corn husks in a large pot or bowl and add water to cover. Place a heavy plate on the husks to keep them submerged. Let stand, turning occasionally, until the husks soften, at least 3 hours and up to 1 day.

To prepare the filling, preheat the broiler. Line a heavy baking sheet with aluminum foil. Arrange the tomatillos on the prepared baking sheet. Broil, turning once, until the tomatillos blacken in spots, about 5 minutes per side. Transfer the tomatillos and any juices on the baking sheet to a food processor and let cool. Add the chiles and garlic and process until a smooth puree forms. 

In a medium saucepan over medium-high heat, warm the olive oil. Add the tomatillo puree and boil for 5 minutes, stirring often. Add the broth, reduce the heat to medium and simmer, stirring occasionally, until the sauce thickly coats the spoon and is reduced to 1 cup, about 40 minutes. Season with salt. Stir in the chicken and cilantro. The filling can be made 1 day ahead; let cool, then cover and refrigerate

NOTE: Use a rotisserie chicken, removing the skin and bones. You should have about 1 pound of shredded meat.

To prepare the dough, in a large bowl, using an electric mixer, beat the lard (with the salt and baking powder, if using) until fluffy. Beat in the fresh masa or masa harina mixture in 4 additions. Reduce the speed to low and gradually beat in 1 1/2 cups of the broth until a tender dough forms. If the dough seems firm, beat in more broth, 2 tablespoons at a time, to soften.

To assemble and steam the tamales, fill a pot fitted with a steamer insert with enough water (about 2 inches) to reach the bottom of the insert. Line the bottom of the insert with some softened corn husks. Tear 3 large corn husks into 1/4-inch-wide strips to use as ties and set aside. 

Open 2 large corn husks on a work surface. Spread 1/4 cup of the dough in a 4-inch square in the center of each husk, leaving a 2- to 3-inch uncovered border at the narrow end of the husk. Spoon a heaping tablespoon of the filling in a strip down the center of each dough square. Fold the long sides of the husk and dough over the filling to cover. Fold up the narrow end of the husk. Tie the folded portion with a strip of husk to secure, leaving the wide end of the tamale open. Stand the tamales in the steamer basket. Repeat with more husks, dough and filling until all of the filling has been used. If necessary, to keep the tamales upright in the steamer, insert pieces of crumpled foil between them.

Bring the water in the pot to a boil. Cover the pot and steam the tamales until the dough is firm to the touch and separates easily from the husk, adding more water to the pot as necessary, about 45 minutes. Let stand for 10 minutes before serving. 

The tamales can be steamed up to 2 days ahead. Let cool for 1 hour, then cover and refrigerate. Before serving, re-steam the tamales until hot, about 35 minutes.