In a large mixing bowl, combine the masa and salt, working well with your hands to mix evenly. (If using masa harina, add the salt before mixing in the stock or water.) Form the dough into 10 Ping-Pong-sized balls.
Drain the corn husks and pat dry. Have them on the counter ready to fill.
Working with one ball of dough at a time and keeping the rest covered with a damp cloth, prepare a tortilla press and press out the dough into a 5-inch round. Gently peel off the plastic liner.
Carefully holding the tortilla in the palm of one hand, place 1 heaping tablespoon of mole amarillo in the center. Place several pieces of shredded chicken over it and top with a piece of the reserved hoja santa. (If using dried hoja santa, sprinkle about ½ teaspoon over the chicken.) Fold together the sides of the tortilla to enclose the filling; it is not necessary to close the open ends.
Carefully place the filled tortilla lengthwise in the center of a corn husk. Fold the sides of the husk together, taking care to keep it seam side up.
Place the tamales on the steamer rack, seam side up, stacking in layers as necessary but making sure that they lie flat on the rack.
Steam, tightly covered, over medium-low heat for about 30-35 minutes.