These silky textured Veracruzano "pudding" tamales are made with a precooked batter that helps cut down the cooking time.
Place the chicken breast in a medium saucepan; cover with salted water. Bring liquid to a boil, and reduce heat to a simmer. Cook until the chicken becomes opaque throughout, about 20 minutes. Remove pan from heat. When chicken is cool enough to handle, shred the chicken.
Using kitchen scissors, cut off the brown, hard edges from the banana leaves. Cut each leaf into eight 10-inch squares. From the trimmings, make 16 1/4-inch-wide strips cut along the grain. Tie 2 strips together, forming 8 long strips; set aside.
Set a small, heavy skillet over medium heat. When skillet is hot, add the dried chiles. Cook, stirring, until chiles are very fragrant and toasted in spots, 2 to 3 minutes. Transfer chiles to a bowl, and cover with 1 1/2 cups hot water. Set a small plate on top of the chiles, keeping them submerged.
Add the garlic cloves to the hot skillet, and cook, turning, until soft and darkened in spots, about 20 minutes. Remove skillet from heat. When the garlic becomes cool enough to handle, peel; set aside.
Drain the chiles, reserving 1 1/4 cup soaking liquid. In the jar of a blender or the bowl of a food processor, combine the chiles, liquid, and the garlic. Process until a puree forms. Transfer puree to a small saucepan, and simmer over medium heat until the mixture reaches the consistency of canned tomato sauce, 25 to 30 minutes. Stir in 1/2 teaspoon salt and the sugar; set the chipotle salsa aside.
Working in two batches, blend the masa with the stock, and strain the mixture through a medium sieve into a large saucepan. Set over medium heat, whisking constantly, until the mixture comes to a boil, about 20 minutes.
Whisk in lard until combined and thick enough to hold its shape when placed in a spoon, about 5 minutes. Add 1 teaspoon salt; transfer to a bowl. Let cool completely.
Lay 1 banana leaf, shiny-side down, on a clean work surface, and lightly pat dry. Place 2/3 cup batter into the center. Spread the batter toward the right side, forming a rough 3-by-6-inch rectangle. Place 1 tablespoon chipotle salsa, 2 tablespoons shredded chicken, and one-fourth of a hoja santa leaf or 3 sprigs cilantro onto the left side of the batter. Fold the right third of the leaf over, covering the middle third and encasing the filling between the batter. Fold the uncovered section of the leaf over the top, then fold both of the open ends under. Tie loosely with a strip around the middle. Repeat with the remaining ingredients.
Line the steamer basket with small pieces of banana leaves. Transfer prepared tamales to steamer, no more than 2 deep. Cover the tamales with remaining banana leaves.
Steam the tamales 1 1/2 hours. Serve the tamales with the remaining chipotle salsa.
Fresh or frozen banana leaves are available at Mexican markets. If they are thick and not supple, roll them loosely, and steam over medium heat until they become pliable, about thirty minutes.