Prepare the Corn Husks:

Soak corn husks in hot water for several hours or overnight until soft. Shake off excess water and pat dry.

Make the Beef Filling:

Cut brisket into large chunks and add to a pot with onion, garlic, salt, and peppercorns. Cover with water, bring to a boil, then simmer for about 3 hours until tender.

Let beef cool in broth, then strain and reserve broth. Chop beef with garlic.

Simmer ancho chiles and cumin seeds in water until softened. Remove seeds and veins. Blend chiles and cumin into a paste.

Melt lard, sauté chile paste for 3 minutes, then add chopped beef. Add ½ cup broth and cook 10 minutes until thick. Season with salt.

Make the Masa:

If using masa harina, follow package directions.

Melt lard. In a large mixer, combine masa, salt, baking soda, broth, and melted lard. Beat for 10 minutes until fluffy. Masa should float in cold water when ready.

Assemble the Tamales:

Spread a thin layer of masa on the wide end of a corn husk (about 3″ x 3½”).

Add 1 Tbsp beef filling to center. Fold sides together, then fold up the bottom 2 inches. Leave top open.

Cook the Tamales:

Fill a tamale steamer or large pot with 1 inch water.

Stack tamales upright with folded bottoms down. Cover with corn husks and cloth or tight-fitting lid.

Steam for 1½ to 2½ hours, refilling water as needed.

Tamales are done when masa easily peels away from husk and is fully cooked.