Press as much water out of the tofu as possible. Slice into square cubes.
Add the garlic, toasted sesame oil, soy sauce, vinegar, crushed red pepper flakes and cubed tofu to a large plastic bag (do not add the sesame seeds or dressing ingredients). Seal and chill in the refrigerator for 30 minutes to an hour.
While the tofu is marinating, whisk together the spicy peanut dressing ingredients and set aside.
Mix together the toasted and black sesame seeds in a small bowl. Dredge each piece of tofu in the sesame seeds (I only dredged two sides).
Heat a large nonstick pan over medium low heat. You can add a small amount of oil or cooking spray but the sesame oil in the marinade should prevent sticking. Add the tofu and allow it to brown a bit before flipping sides. Periodically swirl the tofu around and keep an eye on the heat to make sure the sesame seeds don't burn. It should take several minutes per side.
Serve the tofu over mixed greens. Top each salad plate with peanuts and scallions to taste (1-2 tablespoons each per salad is a good estimate).
Drizzle spicy peanut dressing over salad and serve.