Soak the corn husks in warm water for about an hour until soft.
In a large bowl, beat the shortening or lard until fluffy. Add the masa harina, baking powder, and salt, and mix well.
Gradually add the chicken broth to the masa mixture, and mix until the dough is smooth and spreadable.
Take a softened corn husk and spread 2-3 tablespoons of the masa dough onto the center.
Place your chosen filling in the center of the masa dough.
Fold the sides of the corn husk in towards the center, then fold the bottom upwards.
Repeat with remaining husks and dough.
Place tamales upright in a steamer and steam for 1.5 to 2 hours, checking water level occasionally.
Tamales are done when the masa easily pulls away from the husks.