Taco Bell may have axed Cheesy Fiesta Potatoes from their menu, but that doesn't mean you can't enjoy our copycat version at home.
Place potatoes in a medium saucepan, and add enough cold water to cover. Bring to a boil over high; boil 3 minutes, and drain well. Transfer potatoes on a plate lined with paper towels.
Heat oil in a small saucepan over medium-high. While oil heats, combine taco seasoning, tapioca, rice flour, paprika, turmeric, garlic powder, onion powder, and 1 teaspoon of the salt in a medium bowl.
Add potatoes to seasoning mixture, and toss to coat lightly; shake off any excess seasoning. Add seasoned potatoes to hot oil in 2 batches, and fry until golden brown, about 3 minutes. Transfer to plate lined with paper towels, and sprinkle with remaining salt.
Divide potatoes among 4 small bowls; top each with 3 tablespoons of the cheese sauce and 1 tablespoon sour cream.