1 hour ahead of cooking, cut tofu in half lengthwise (hamburger style), and press between two towels with something heavy on top (I use my dutch oven or a cast iron pan). Let the water press out of the tofu- the towels should be soaked after an hour. Do not skip this step! It is super important that you get as much moisture out of the tofu as possible beforehand. 

Once cut in half and pressed, use your hands to tear off 1-2 inch pieces of tofu and lay them out in a single layer on a parchment lined baking sheet. Freeze for about 20-30 mins until exterior becomes hard. 

Preheat oven to 400 degrees and put your rack in the middle position of the oven. Line a large baking sheet with parchment paper. 

In a medium bowl combine the rice flour, cornstarch, sesame seeds, oil, water and salt. Stir together until smooth. *The consistency should be that when you dip a piece of the tofu into the batter it doesn't all drip off right away, but instead clings to the tofu. You also don't want huge pools of batter on the sheet when you pull a piece out of the batter.  It shouldn't be too thick either so that you can't dip a piece into the batter and have it stick. Adjust accordingly if you run into either of these situations by adding more flour or more water.

Add the frozen pieces of tofu to the batter. When all the pieces have been added use a spatula to gently combine them with the batter until they're all coated. * I have also done this where I add a piece one at a time to coat it, but I find it takes too long and doesn't have any better effect on the final product.*

Remove a piece at a time from the batter and lay it on the parchment paper gently shaking off any excess as you remove it from the bowl. The pieces should be firm enough that they don't fall apart (because of the pressing and freezing) but you should still be gentle. 

Bake the tofu pieces for 20 minutes on one side and then turn each piece over and bake on the other side for 15 more minutes. While the tofu is baking you can make the sauce. 

Combine all the ingredients (besides the water and cornstarch) in a small sauce pan and cook over medium heat. Bring to a low boil and let it cook, stirring frequently for 3-4 minutes. It will bubble up so make sure to keep an eye on it. 

To thicken up the sauce a bit make a slurry using the cornstarch and the water by combining the two in a small bowl until there are no lumps. Reduce the heat of the simmering sauce and add the slurry whisking as you add it. Bring back to a boil and then remove from the heat. You should notice that the sauce has thickened significantly. If it needs to be thinned out add a little more water, or if it needs to thicken up let it cook a little longer on the stovetop. *The sauce should be thick enough that it coats the back of a spoon. You can let it cool if it finishes before the tofu- it will thicken up as it cools but will thin out again when you toss it with the hot tofu. 

When the tofu has come out of the oven combine it with the sauce (you might not need it all on the tofu, but I used it to pour on broccoli or other veggies you might serve with the tofu), so use your judgement here. Sprinkle with sesame seeds and chopped green onions and enjoy right away.