Prepare the fry bread dough: mix flour, baking powder, salt, warm water, and 2 tbsp oil. Knead lightly for 2–3 minutes, cover, and let rest for 30 minutes.
Cook the meat filling: sauté onions and garlic, add ground meat, season with chili powder, cumin, paprika, salt, and pepper; cook until browned.
Shape and fry bread: divide dough into 6–8 portions, flatten to ¼ inch thick circles. Fry in ½ inch vegetable oil for 2–3 minutes per side until golden. Drain on paper towels.
Assemble tacos: place fry bread on a plate, top with meat, lettuce, tomatoes, cheese, sour cream, and optional toppings. Repeat with remaining portions.
Serve immediately for best crispiness.