Method:
In a kettle place mashed or blended tomatoes and add 2 cups water. Place under low heat and let simmer. Coat large skillet with cooking oil and using high heat, start braising the pork. Braise the meat in three batches. After the meat is well browned, add to the tomatoes and braise the next portion. When the third portion is braised, push the meat to the sides of the skillet and in the center place the onion and the garlic to glaze (cook till onion looks glossy). Turn down the heat to medium and add the flour, red chili powder and oregano and blend all the ingredients well. Add green chilies. Add the other two cups of water, stirring until smooth. Bring to a boil and then turn down heat and let simmer for two hours stirring occasionally to keep from sticking to bottom of kettle. You may have to add more salt to taste.