Preheat the oven to 425 degrees and prepare a large roasting pan either with parchment paper or a silicone mat. If your pans are smaller you will need two.
Add the peeled and cut potatoes to a large pot. Cover with water and then add the baking soda and 1 teaspoon salt. Stir and bring to a boil.
Simmer for about 10 minutes, just until a little resistance is met when you insert a fork into the potato chunk. You don't want them super soft and overcooked at this point.
Drain the potatoes, and add to a large bowl with a lid, preferably.
To the large bowl with the potatoes, add the remaining 1 teaspoon salt, garlic powder, onion powder, and either stir very well, or put the lid on and carefully shake the bowl until all ingredients are well combined. There will be a thick paste on the potatoes at this point; that is what you want.
Transfer the potatoes to the roasting pan(s), spreading them out evenly.
Roast for 30 minutes, then turn the potatoes and roast for about 30 minutes more.
Remove from oven and serve.