Preheat oven to 350 F / 175 C.
If using extra firm tofu, press for at least 30 minutes. If using super firm, just pat the block dry. Thinly slice it and set aside.
To make the marinade, combine everything else in a large bowl. Add the tofu slices into the bowl and gently toss to coat them in the marinade. It's okay if the pieces get broken up, in fact it's a good thing!
Line a baking sheet with parchment paper and spray the paper with cooking spray. Spread the sauced tofu slices in an even layer, making sure they don't overlap. Add them to the oven and bake for 30 minutes, or until the tofu feels slightly dry and chewy.
Once tofu is dried out, add them to a skillet over medium heat, and add 1 cup of water. Bring to a simmer over medium heat until most of the water has been reabsorbed / reduced.
Your Tofu Gyro is done! Enjoy in a pita with tomatoes, the marinated onions, some tzatziki and fries!