Now, create the tsuyu. In a small saucepan, bring dashi, soy sauce, and mirin to a boil, stirring occasionally. Once it reaches a boil, remove from heat, cover, and set aside.
Unwrap the tofu from the paper towels and cut into eight large cubes.
In a deep fryer, heat 1 1/2 inches of vegetable oil to 350 degrees F.
While that heats up, gently dust the tofu with potato starch. (I put my starch in a bowl and gently toss each individual cube in the starch until coated.)
Carefully deep fry the cubes until light brown and crispy. Remove the tofu and place on a paper towel to drain any excess oil.