Rinse corn husks, soak them in warm water for 2+ hours, and pat dry before use.
Trim fat, cut into chunks, and pressure-cook with seasonings for 90 minutes. Shred pork and mix with some broth.
Boil ancho and guajillo chilies with onion and garlic. Blend and strain into a smooth puree. Mix some sauce into the shredded pork.
Beat lard until fluffy, then mix with pork broth, chili sauce, and masa harina until smooth and spreadable. Test by dropping dough in water—it should float.
Separate husks into “usable” for wrapping and “unusable” for ties.
Spread masa on a husk, add pork filling, fold, and tie with strips.
Stand tamales upright in the steamer basket, open ends up.
Cook for 35 minutes in the Instant Pot on High Pressure.
Unwrap and enjoy with chili sauce, sour cream, and your favorite sides!