In a large bowl, combine flour, baking powder, sugar (if using), and salt. Add the water gradually, using your hands to combine. The dough will be sticky.
Cover the dough with plastic wrap (or the dough will harden) and put aside for 30 minutes while making the meat topping.
In a large saucepan, saute garlic and onion for 4-5 minutes on medium until fragrant. Add the ground beef and break into pieces with a spatula until browned.
Add taco seasoning, then black beans, green chiles, and tomatoes. Saute for 3-4 minutes. Add broth and bring to a simmer, then lower heat to medium-low and continue simmering until broth is absorbed (about 10 minutes). Take off heat and set aside.
Meanwhile, drizzle olive oil over the dough. Take a 2-inch piece and thin it out with a rolling pin, as thin as you can without tearing. Repeat with remaining dough.
Pour enough vegetable oil into a deep skillet, preferably cast-iron, to come up 2 inches. Heat to oil 350℉/177℃.
Fry the dough one at a time in the hot oil until slightly brown, then flip to brown the other side. Place on a plate covered with a paper towel to soak up excess oil.
To serve, place one fried bread piece on a plate and top with at least ½ cup of meat mixture. You can also add black olives, sliced lettuce, avocado, and a dollop of sour cream.