Place the chicken breasts and bouillon cube in a sauce pan. Cover with water and bring to a boil. Simmer the chicken for 45 minutes to an hour until tender enough to shred.
While the chicken is cooking, heat the oil in a saute pan, add the onions. Saute for 5 minutes on medium heat or until onions are soft and translucent.
Add in the tomatoes and cook until mushy about 10 minutes. Add in the garlic and cook for 1 minute. Then using a bean or potato masher mash the tomatoes until they are broken up (about 10 good mashes). Add the oregnao, salt to taste. Then turn the heat off of the tomatoes and set them aside.
Pull the meat out of the sauce pan and set aside to cool.
In a large bowl combine the fresh masa, corn flour and white flour. Once all is combined add ¼ cup water at a time until dough is easy to knead and slightly sticky. I usually add around ½ to 1/3 cups water.
Add in the salt and knead the dough for 2 minutes to make sure the salt is incorporated.
Shape the dough into egg size balls and flatten slightly into discs.
Shred the chicken into thin shreds and add it to the tomato mixture. Stir and set aside.
Press each disc in a tortilla press or between two sheets of plastic until it is flat and around ¼ inch thick.
As you press each empanada fill with approx 1 tbsp of the chicken mixture on one side, then fold the other side over and press the edges together. Then peel away the plastic and drop the empanada in oil for frying.
I serve these with salsa, chile de arbol, sour cream and shredded lettuce. Enjoy!