Heat vegetable oil in a large skillet over medium heat.
Add the pork cubes and cook until browned on all sides. Remove and set aside.
In the same skillet, add the chopped onion and garlic. Sauté until the onion is soft and translucent, about 5 minutes.
Stir in the chopped tomatoes and cook for another 2 minutes.
Add the tomato sauce, ground cumin, paprika, dried oregano, black pepper, and cayenne pepper (if using). Cook for 5 minutes until the sauce thickens.
Return the browned pork to the skillet. Stir to combine and cook until the pork is tender and fully cooked, about 10-15 minutes. Season with salt to taste. Set aside to cool.
In a large bowl, combine masa harina, baking powder, and salt.
Gradually add chicken broth and vegetable oil or lard, mixing until the masa is soft and pliable. You may need to adjust the amount of broth to achieve the right consistency.
Take a soaked corn husk and spread a small amount of masa in the center, leaving space at the edges.
Add a spoonful of the pork filling on top of the masa.
Fold the sides of the husk over the masa and filling, then fold the bottom up to create a sealed packet. Secure with a strip of corn husk if needed.
Repeat with the remaining husks, masa, and filling.
Arrange the wrapped chuchitos upright in a large steamer or pot with a steaming rack.
Steam over boiling water for about 45-60 minutes, or until the masa is cooked through and firm to the touch. Check occasionally to ensure there's enough water in the pot.
Let the chuchitos cool slightly before serving. Enjoy with your favorite salsa or hot sauce.
Enjoy your meal!