1. Combine 1 tablespoon canola oil and next 7 ingredients (through sesame oil) in a medium bowl, stirring with a whisk.
2. Cook noodles according to package directions; drain and rinse. Combine noodles and 1/4 cup miso mixture in a bowl; toss to coat.
3. Heat a large nonstick skillet over medium-high heat. Add 1 tablespoon canola oil to pan; swirl to coat. Cut tofu crosswise into 4 (1-inch-thick) slices. Add tofu to pan; cook 3 minutes on each side or until browned. Add 1 tablespoon miso mixture to pan; toss to coat. Remove tofu from pan; keep warm. Add remaining 1 1/2 teaspoons canola oil to pan; swirl to coat. Add mushrooms and asparagus to pan; sauté 4 minutes or until tender. Add remaining 2 tablespoons miso mixture to pan; toss to coat. Sprinkle with green onions. Arrange 1/2 cup noodle mixture in each of 4 bowls; top each serving with 1/2 cup vegetable mixture and 1 tofu steak.