In a mixing bowl, whisk together the Greek yogurt, dijon mustard, maple syrup, lemon zest and juice, olive oil, soy sauce, minced garlic, Parmesan, smoked paprika, onion powder, oregano, thyme, salt, and pepper until smooth. Reserve 2 tablespoons of this marinade for later.
Gently pat your super firm tofu dry using a paper towel, then cut it into bite-sized chunks.
Toss the tofu pieces in the marinade until well-coated. Allow them to soak for at least 15 minutes.
If using skewers, carefully thread the marinated tofu onto them. Heat a skillet over medium heat, add olive oil, and cook for about 3 minutes on each side until golden brown and crispy.
Once browned, toss the cooked tofu with the reserved marinade.
Serve the tofu pieces on warm pita bread, topped with tzatziki.
