Cook the pork

• Put the pork shoulder pieces in a large pot and cover with boiling water.
• Add the whole onion, the garlic heads, salt and pepper.
• Cover and cook over medium heat until the meat is tender, skimming off any foam that rises.

Strain and cool the meat

• Remove the onion and garlic heads, then take out the meat.
• Let the meat cool before shredding. Keep the broth.

Make the red chile sauce

• Boil the guajillo and ancho chiles in the same broth for about 10 minutes.
• Transfer the chiles to a blender with broth and the garlic cloves, then blend until smooth.
• Set aside a cup of the sauce for the masa and keep the remaining broth.

Shred the pork

• Shred the cooled meat, leaving a little fat for juiciness.

Make the pork picadillo

• Heat oil in a pan over medium heat and fry the minced garlic, half onion and jalapeños for about 2 minutes.
• Add the shredded meat and cook for about 3 minutes.
• Add the Roma tomatoes and cook until they release their juices, about 5 minutes.

Add the sauce to the filling

• Add the red sauce to the pan, rinsing the blender with a cup of broth.
• Stir in the chicken bouillon, mix well and adjust salt.
• Cook for 5 more minutes, then cover, turn off the heat and set aside.

Warm the broth for the masa

• Warm the remaining broth in a pot and mix in the reserved cup of salsa.
• Heat through; the broth must be warm when added to the masa.

Beat the lard

• Add the lard to a stand mixer and beat at medium speed until fluffy.
• Add the salt and baking powder and beat for about a minute.

Mix the masa

• Reduce the mixer to the lowest speed and alternate adding masa and warm broth, one cup at a time.
• When the broth runs out, continue with the warm water.
• Increase to high speed and mix until the masa is light and well hydrated.

Test and rest the masa

• Drop a small piece of masa into a cup of water; it should float. If not, add a little water, mix and test again.
• Cover and let the masa rest.

Assemble the tamales

• Pat the soaked corn husks dry and spread a thin layer of masa on the soft side.
• Add some pork filling and fold the husk closed.
• Repeat until the masa or filling runs out.

Steam the tamales

• Pour boiling water into the pot, just below the steamer, and line it with a layer of husks.
• Stand the tamales upright in the steamer, cover with more husks and a wet cloth.
• Cover and cook over medium heat until the masa pulls away easily from the husk.