In a heavy-bottomed, medium-size pot over medium heat, add the first seven ingredients (olive oil through 1 teaspoon black pepper). Sweat until the vegetables are tender, about 5 to 7 minutes. Add the next 12 ingredients (crushed tomatoes through cumin) and bring to a boil. Reduce the heat and simmer for 20 minutes. Meanwhile, mix the masa harina and warm water together to make a slurry. Add the brisket to the pot, and mix in the slurry. Simmer for 5 to 10 minutes, stirring often. (Note: Do not to let the meat settle on the bottom.)