1 pound string beans and yellow wax beans, trimmed
⅓ cup canola oil
1 red bell pepper, cut into ¼-inch wide strips
1 tablespoon black sesame seeds, toasted
½ teaspoon black sesame seeds optional
2 teaspoon soy sauce
1 teaspoon wasabi powder
¼ cup unseasoned rice vinegar
¼ teaspoon sugar
¾ cup canola oil
½ teaspoon dark Asian sesame oil
Freshly ground black pepper to taste
To make the vinaigrette, combine the soy sauce and wasabi in a medium bowl. Whisk in the vinegar and sugar. Gradually whisk in the canola oil, then the sesame oil. Season with the pepper. Cover and refrigerate until ready
Place the tofu on a rimmed plate. Top with another plate and let stand to gently press excess liquid from the tofu, at least 15 minutes and up to 30 minutes. Pat the tofu dry and cut into 1-inch cubes.
Meanwhile, bring a large saucepan of lightly salted water to a boil over high heat. Add the string beans and cook just until crisp-tender, about 3 minutes. Drain and rinse under cold running water to stop the cooking. Cut into thirds. Cover and refrigerate until ready to serve.
Line a baking sheet with a double-thickness of paper towels. Heat the oil in a large skillet over high heat until very
hot but not smoking. In batches without crowding, add the tofu cubes and fry, turning occasionally, until they turn golden, about 2 minutes. Add more oil to the skillet as needed. Using a slotted spatula, transfer the tofu cubes to the baking sheet.
Add the tofu cubes to the vinaigrette and toss with the vinaigrette (the tofu will soak up the dressing, so you need more than for a green salad). Add the string beans and red pepper and toss again. Use a slotted spoon to transfer equal amounts of the salad among salad plates. Sprinkle with the sesame seeds, along with the black sesame
seeds, if using. Serve immediately.