To prepare salad, cook snow peas in boiling water 3 minutes or until crisp-tender. Drain and rinse with cold water; drain. Thinly slice snow peas crosswise. Combine peas and next 7 ingredients (through 1 1/2 tablespoons mirin) in a medium bowl; set aside.
Heat oil in a large nonstick skillet over medium-high heat. Sprinkle the fish with salt. Add fish to the pan; cook 2 minutes on each side or until desired degree of doneness. Let stand 2 minutes. Cut into 1/4-inch-thick slices.
To prepare dressing, combine tofu and next 4 ingredients (through 1 tablespoon mirin) in a food processor, and process until smooth. With processor on, slowly pour water through food chute; process until well blended. Serve fish over salad; drizzle with dressing just before serving.