Ginger-sesame dressing:
In a food processor (or with mortar and pestle), combine lemon zest, ginger, sugar, cayenne, and salt and process to a smooth puree; add lemon juice, rice vinegar and soy sauce. Blend well. Slowly add canola oil and sesame oil until well combined.
Soba Noodle Salad:
Add tofu to a large non-stick skillet without any oil and toss over high heat until all water has evaporated; add canola oil, reduce heat to medium-high and fry, tossing frequently until tofu is firm and bouncy; beware of possible splattering; drain over paper towels; in a large mixing bowl combine drained soba noodles, cilantro, scallions, cucumber and 2-3 oz dressing, toss well; arrange salad in center of large plate and top with fried tofu. Garnish with sesame seeds and cilantro sprigs.