In a bowl whisk together the flour, baking powder and salt; stir in warm water; knead the mixture on a floured surface until it forms a soft but not sticky dough. Let the dough stand, covered with a kitchen towel, for 15 minutes.
Pull off egg-size pieces of the dough and pat and stretch them into 1/4-inch thick rounds. Poke a hole with a finger through the center of each round so that the breads will
For Fry Bread, in a large heavy skillet heat the shortening over moderately high heat until it is hot but not smoking. Fry the rounds, 1 at a time, for 2 minutes on each side, or until they are golden, and transfer the breads as they are fried to paper towels to drain.
For Indian Taco filling, in a large frying pan over medium-high heat, brown ground meat, tomato sauce and onions until cooked; remove from heat. Place Fry Bread, cupped side up, on separate plates. Layer ground meat, lettuce, tomatoes, Cheddar cheese, and cilanto and green chilies onto top of each Fry Bread. Top with sour cream, if desired, and either roll up or serve open-faced with a fork.