How to Make It
In a large pot of boiling, salted water, cook the spaghetti until just done, about 15 minutes. Drain the pasta. Rinse with cold water and drain thoroughly.
In a medium bowl, combine the tofu with the 1 tablespoon soy sauce and 1/2 teaspoon of the grated ginger. Let sit for about 5 minutes.
In a large glass or stainless-steel bowl, combine the remaining 2 teaspoons ginger and 4 teaspoons soy sauce, 1 1/2 tablespoons of the cooking oil, the vinegar, lemon juice, sesame oil, lemon zest, salt, and cayenne.
In a large nonstick frying pan, heat the remaining 1 tablespoon cooking oil over moderate heat. Add the tofu and cook, stirring frequently, until browned, about 8 minutes. Add the tofu, pasta, cucumbers, scallions, and cilantro to the dressing in the large bowl and toss.