Heat the oven to 425 degrees F. Line a large baking sheet with parchment paper.
Lay the sliced potatoes on the baking sheet lined with parchment paper. Drizzle olive oil, salt, pepper, and garlic powder over the potatoes and toss to evenly coat. Place the fries in rows on the baking sheet, ensuring that each fry is at least 1/2" apart from one another. If the fries are touching, they will not become crispy. Bake for 15 minutes. Remove the fries from the oven and use a pair of tongs to flip each fry over. Bake for another 7-10 minutes, or until they are golden brown.
Meanwhile, make the garlic dipping sauce. Place tahini, garlic, lemon juice, water, salt, and pepper in a bowl. Vigorously whisk the ingredients together until a creamy white sauce forms.
Serve the fries alongside the bowl of garlic sauce. Enjoy!