In a large heavy skillet, render two-thirds of the salt pork over moderate heat. Remove the salt pork and place it in a large pot.

Working in batches, brown the meat in the skillet and transfer the meat to the large pot.

Render the remaining salt pork in the skillet. Add the onions and sauté over a moderately low heat until caramelized. When caramelized, add the garlic and cook for a few minutes.

Turn the mixture into the pot. Add the tomatoes and their juices and cook for 5 to 7 minutes. Add the tomato paste and stir it into the meat. Add the seasonings, chile, and oregano and salt, and mix thoroughly.

Mix the masa harina with 2 tablespoons of water and fold into the chili. Simmer over moderately low heat for 3½ to 4 hours, stirring from time to time and checking to be sure the chili does not stick to the bottom of the pot.

Before serving, check the seasonings. Depending on the freshness of the chile powder, the strength may vary. You may want additional seasonings.

Serve with sliced scallions and shredded cheddar cheese.