Preheat the oven to 425°. Place the potatoes in the wash bowl or salad spinner and fill the bowl with water. Scrub the potatoes really well with a vegetable brush or scrub glove.
Cut the potatoes to 1 1/2 inch to 2 inch thick wedges or cubes.
Return the potato pieces to the wash bowl filled with clean water. Drain the water and refill a couples of times or until the water is no longer cloudy.
Place the rinsed and drained potato pieces in a large prep bowl. They don’t need to be throughly drained. A little water helps adhere the spices to the potatoes. Sprinkle with the turmeric powder first, then give the bowl a toss or stir with a spatula.
Sprinkle with the coriander, cumin and black pepper. Let the potatoes with rest in the bowl for 10 minutes to 20 minutes. This time allows the spices to absorb moisture so they don’t burn during the roasting.
Line a bake sheet with unbleached parchment paper and place the spiced potatoes on a single layer. Roast in the oven for 25 minutes.
The potato side on the paper should be brown in spots. If not, put back for a few minutes without turning the potatoes. (set a timer).
When the undersides are browned in spots, turn them over. Lifting the parchment paper corner will help release the potatoes, then flip with a spatula. Roast for another 15 minutes.
You can check if the potatoes are done by pushing a toothpick through a couple of pieces. The toothpick will go easily if done. You can also taste them (more fun).
The potatoes are ready to serve.