Put the dried corn husks in lukewarm water and soak for at least 2 hours until soft (keeping them under water with a plate).
Mix the pork and chicken with the chili sauce and spices, season with salt and pepper - this is the filling; refrigerate it.
Mix the masa harina with the paprika, chili powder, garlic powder, cumin and salt.
Cut the fat into the dry mixture until you have small, pea-sized pieces.
Gradually add the warm stock, mixing with a mixer, until the dough is peanut-butter-like and airy.
Lay a soaked husk out flat and spread about half a dl of masa on the smooth side, leaving a strip of about 2.5 cm free along one long edge and at the end.
Spoon a tablespoon of filling into the center of the masa.
Roll up the husk from the wider side so the masa closes around the filling, and the free strip wraps around the tamale.
Fold one end up about 2.5 cm, giving the characteristic shape closed at one end and open at the other.
Arrange the tamales standing up with the open end up in a steamer basket, and cover.
Steam over boiling water, kept separate from the water, for about 2 hours.
Unwrap one tamale to check that the masa is cooked through (not sticky).
Let them stand for 30 minutes before serving so the masa does not stick to the husk.