1. Soak corn husks in hot water for at least an hour. Place a plate over them to weigh them down so they are completely submerged.2. Using a stand mixer, combine masa harina flour, stock, shortening, baking powder, and salt. Mix on medium speed for 5 minutes. Masa should be smooth and not stick to hands. To test, drop a 1" ball of masa in a cup of water. If the masa floats, it’s ready to be spread. 3. Remove corn husks from water and set on towels. Reserve largest husks to wrap tamales and small ones to line the steamer. To wrap tamales, pull 24 pencil-thin strips off corn husks and set aside. 4. Hold corn husk with tapered side away from you. Scoop ¼ cup of masa mixture on corn husk and spread with a spoon, forming a square 3–4 inches across and leaving a 1-inch border on the sides. Place 2–3 pieces of potato, cheese, and 3–4 Poblano pepper strips on the dough. Fold one side of the corn husk over filling then fold the other side, overlapping. Fold the tapered side up and tie with a corn husk strip to keep it from unfolding. Repeat with remaining husks and masa.5. Arrange tamales upright in a steamer. Fill with hot water right below the rack and steam over medium-high heat. Cover top of tamales with a layer of remaining husks and then cover with lid. Bring water to a boil and reduce heat to medium, adding water as needed. Steam for 90 minutes, or when tested, corn husks should unwrap and masa separates from dough easily.6. Remove tamales from steamer. Let cool before serving. Top with your favorite salsa and enjoy!