Freeze tofu overnight and thaw in microwave for 2-3 minutes. Wrap the tofu block in a clean kitchen towel and place a heavy object (like a pan) on top. Let it sit for 2-3 minutes remove excess moisture. Alternatively, you can use the tofu block as is and remove excess moisture.
In one shallow bowl, add flour, sparking water, salt, black pepper and seasonings. Mix well.
Add panko breadcrumbs into another bowl.
Slice the tofu into half so it looks like 2 rectangular or square-ish slabs. Dip them into the plant milk mixture, ensuring all sides are covered.
Press into panko breadcrumbs, coating thoroughly on both sides.
Heat oil in a pan over medium heat. Fry the tofu pieces for a few minutes on both sides until golden brown and crispy.
Remove and place on a wire rack or paper towel to drain excess oil. Once slightly cooled, slice into pieces.
For the vegan tonkatsu sauce, combine all ingredients together and whisk until fully mixed.
Serve tofu katsu over a bed of white rice with a generous drizzle of tonkatsu sauce. Pair with shredded cabbage and top with scallions & toasted sesame seeds. Enjoy!