Preheat oven to 425 degrees. Line a large baking sheet with parchment paper.
In a small bowl, combine flour, corn starch, and taco seasoning. Set aside.
In a large bowl, toss diced potatoes in oil to coat. Add salt and pepper and toss again. Sprinkle seasoning mixture over potatoes and gently toss, making sure to evenly coat all the potatoes.
Spread potatoes onto prepared baking sheet. Bake 20 minutes. Flip potatoes with a spatula, and bake additional 10-15 minutes until golden brown and crispy.