The key to cripsy tofu is drain as much water out as possible. Therefore we recommend letting the tofu drain for at least 24 hours in your refrigerator. Do this by removing it from the container, slice it in half, and sit both halfs on a stack or 1 or 2 folded paper towels on your cutting board. Next, Place 1 or 2 folded paper towels on top of the tofu halves and set something heavy on top of them. I like to use my cast iron skillet. Set the cutting board in the refrigerator.
Change the paper towel once or twice during the 24 hour draining period.
Remove the tofu from the refrigerator and cut it into cubes. I recommend ~1" cubes, but do whatever you prefer.
Cooking the Tofu
Preheat the oven to 400F. Line a baking sheet with parchment paper. Use a papertowel to rub or oil spritzer to spray oil on the parchment paper. This prevents the tofu from sticking to the parchment paper and saves you from scrubbing the oil off of your pan.
Place the cubbed tofu in a large bowl and toss with 1 tablespoon of tamari and 1 tablespoon of arrowroot starch to coat the cubes evenly. Using a rubber spatula can help with even distribution.
Add 1 tablespoon of tamari to a non-stick skillet and place the burner on medium/high heat. Once hot, add the tofu to the skillet and saute, stirring continuousy, for 5 minutes.
Transfer the tofu to the lined baking sheet and spread it out into an even layer. Bake it for 20 minutes, removing and stirring halfway through.
Notes
Sometimes you don't have 24 hours to drain your tofu... been there. You can still prepare oil-free crispy tofu. Drain the tofu for whatever time you have whether thats 10 minutes or a couple hours. Then when baking it set the oven temperature to 300F and leave the tofu in the oven for 45 minutes to an hour.