Combine masa harina with warm water. Mix ground meat with prepared masa, salt, pepper, garlic. Make meatballs about 1-inch round, about the size of a walnut. Set aside.
In medium saute pan heat 2 tablespoons lard or oil over medium heat. Add 1 whole garlic clove. Let cook for 20 seconds, press with back of a cooking spoon to release the flavor. Remove the garlic. Set aside.
Brown the flour in the lard until dark golden color, about 1 minute. Heat stock in soup pot or large Dutch oven until warm and add flour mixture. Bring to a boil and lower heat to simmer stock for 5 minutes. Taste and correct seasoning.
Heat remaining 2 tablespoons lard or vegetable oil in large frying pan, add chopped scallion, tomato, chiles and the reserved 2 garlic cloves, minced, stir well to combine. Cook for 2 minutes and add to stock. Add cilantro and mint and simmer for another 5 minutes. Add the meatballs to the stock and simmer over low fire for 15 minutes or until done.