Preheat oven to 450F.
Boil potatoes: Add about 6 cups of water to a large pot and bring to a boil. Stir in salt and baking soda, then add potatoes. Return to a boil, reduce to a simmer, and cook for 8-10 minutes, or just until the potatoes can easily be pierced with a knife.
Drain the potatoes and let cool for about 2 minutes.
Make the lemon tahini sauce: Whisk together lemon juice, tahini, dijon mustard, garlic powder, onion powder, Italian seasoning, and black pepper.
Toss potatoes in the lemon tahini sauce until fully coated.
Roast the potatoes: Line a baking sheet with a silicone baking mat or parchment paper. Spread potatoes out in a single layer, skin-side down. Bake for 30-35 minutes, flipping them around 20 minutes, until they are golden and crispy.
Remove from oven and, if desired, top with a sprinkle of salt or fresh herbs and another squeeze of lemon. Serve and enjoy!