Cut the tofu into 4 rectangular pieces and remove the excess moisture by placing heavy pans directly on top of the tofu. Let stand about 20 minutes.
Heat both oils up in a non-stick pan over medium heat. Fry the tofu on all sides to seal.
Place the tofu on a serving platter.
In a small saucepan over medium-high heat, combine the soy sauce, rice vinegar, ginger and water (or broth). Just before the mixture comes to a boil, whisk in the miso.
Pour the sauce over the cooked tofu. Garnish with scallions, watercress or daikon sprouts, and the black sesame seeds.