Place pork along with garlic and onion in a skillet and add water to it. Bring it to boil. When it starts boiling, reduce the heat and allow it to simmer for about 2 hours, until the meat is cooked well.
Alternate: Cook pork loin, garlic and onion with 1 cup water in crockpot at least 8 hours (you can do this the night before)
2Remove stems and seeds from the chili pods and place pods in a saucepan. Add 2 cups of water and let it simmer for about 20 minutes. Remove from heat and allow to cool down. Blend chilis and water in a blender, until a smooth paste is formed.
Then, strain this mixture and add salt. Shred the cooked pork and add to it one cup of chili sauce.
3In a large bowl, mix a tablespoon of beef broth with the lard, until it becomes fluffy.
Mix together masa harina, salt and baking powder and add the lard mixture to it. Add more broth if required, to make a spongy dough.
4Now let's prepare the corn husks for wrapping. Clean the corn husks and soak them in a bowl of warm water to soften them.
Spread the dough over the corn husks to the thickness of about ¼ to ½ inches. Add 1 tablespoon of meat filling on top of the dough at the center.
Fold the sides of husks towards the center and tie with a string.
Add enough water to bottom of steamer, but do not allow it to touch tamales.
Place tamales into the steamer open side up and allow them to cook at a simmer for about 1 hour.
Remove tamales from the husks and sprinkle the remaining chili sauce over them.
Then add sour cream on the top(optional).
5NOTE: If you don't have a steamer, here's an alternative
Invert an aluminum pie pan into the bottom of a large stew pot and place some husks on top of the pie pan.
Arrange the tamales in the pot by placing them one by one open side up on top of the pie pan, starting in the middle and working out, building a pyramid, Fill the pot about 1/2 full with tamales.
Pour enough water seasoned with a little salt and chili powder into the bottom of the pot (not on the tamales) to not quite touch the bottom of the tamales.