Preheat a medium-sized nonstick skillet over medium-high heat. Wait until the pan is very hot. Add 2 tbsp of oil and swirl the pan to coat it evenly with the oil. Slice the block of tofu into 6 even slices. Place the tofu carefully into the hot pan. The tofu should sizzle well once it hits the pan. Be sure to turn down the heat slightly (to about medium) and allow the tofu to cook on the first side for several minutes until browned and crispy. Sprinkle the tofu with kosher salt.
Flip the tofu and cook it on the second side for several minutes. Instead of timing how long the tofu takes to get crispy, simply cook it until the tofu is nicely golden brown. The more patience you are the crispier the tofu.
Remove the tofu to a clean plate to make room in the pan to make the sauce. The pan should still be on the stove and hot.
In the hot pan, add 1/2 tablespoon of oil and then the minced ginger and garlic. Stir briefly until fragrant about 30 seconds. Then turn off the heat and add the soy, brown sugar sweetener, and rice vinegar. The mixture will bubble slightly and evaporate some. That is ok, that is what you want to happen. There will not be much sauce in the end, just enough for a light glaze.
Add the seared tofu back to the pan and toss to coat. Shingle tofu on a clean plate and top with remaining sauce (most will have clung to the tofu). Drizzle plated tofu with sesame seed oil and top with sliced scallions.