Begin by draining a block of tofu and then removing excess moisture by pressing it. To do this simply place the tofu on a paper towel lined plate. Top with another paper towel and another plate. Weigh down with something like a large can of tomatoes.
Meanwhile, prepare the marinade/sauce by whisking all ingredients together.
Grate the tofu on a simple hand grater and using 1/3 of the marinade, pour over the grated tofu. Set aside for 15 minutes.
Drain the tofu liquid and add to a hot, dry pan. Stir occasionally, but not too much so that the caramelization process can occur. Remove to a bowl.
In the same pan, add 1 tsp of oil and the frozen bag of vegetables. Cook for 4 minutes, stirring occasionally.
Add the marinade and cook until thickened.
Add back the tofu and give a good stir.
Serve with white rice and a sprinkling of white sesame seeds, if desired.