Heat sesame oil in a nonstick pan and add sesame seeds, ginger, garlic and scallions to it. Sauté for 30 seconds.
Add cabbage and carrots and sauté again for 1-2minutes.
Add rest of the filling ingredients and keep sautéing until tofu dries up nicely and is well cooked. Remove from heat and keep it aside.
Prepare the instant pot by adding about 1 ½ cups water to its inner pot. Grease the vegetable steamer with a cooking spray. Place the vegetable steamer inside the inner pot. ( Make sure the water does not seep in through the steamer or else reduce the water in the pot). Keep it aside. In a mixing bowl combine brown rice flour, quinoa flour, cornstarch and salt and mix with a spoon.
Now, pour ½ cup water to it and mix with a spoon. It will be very hot at this point so continue mixing with a spoon until it becomes little comfortable to mix with hands. Do not let it cool down completely. It kneads better if still warm. After mixing with hands the dough will be very crumbly. Then, add the rest of 1/8 cup hot water and slowly knead it into a smooth round dough. Cover it with a kitchen cloth and let it rest for1 minute.
Diving the dough into 12 equal parts and take one part between your palms. Keep the rest of the dough covered to avoid it from drying up. Grease your palms with oil and knead the small portion of the dough between your palms into a smooth round ball. Then, place it on a flat surface. With the help of a rolling pin roll it into a palm sized flat round shape or up to to 3-4inches in diameter. Do not try to roll it very thin or else it will break. The edges might be uneven which is ok.
Now, take 1 tbsp of the filling and spread it at its center. Gently, fold it length wise and seal the edges with your fingers. Keep it aside. (Repeat this process for the rest of the dough).
Place all the dumplings on the prepared vegetable steamer and close the lid of the instant pot. Seal the valve and turn it on at high manual for 5 minutes. Once done, let it release it pressure on its own which will take another 5-10 minutes. Unlock the seal and open the lid. With the help of a spoon gently take each dumpling out of the steamer on a serving plate. Garnish and serve.