Step 1Toast the sesame seeds in a small nonstick skillet until lightly browned, about 1 minute, watching carefully so they don't burn. Remove them from the skillet, placing on a paper towel to cool.
Step 2Heat 1 teaspoon of sesame oil and the water in a skillet to a simmer. Add the noodles (discard the seasoning packets) and cover loosely to steam the noodles, about 1 minute. Uncover and stir the noodles, spreading them around the pan until they have separated and are heated through, 2 to 3 minutes. Set aside and let cool.
Step 3Tear the lettuce into bite-size pieces to measure 4 cups and place in a large bowl. Stir in the cucumber, celery, carrot, pea pods and tomato. Toss in the noodles, shrimp and sesame seeds.
Step 4For the salad dressing, combine the rice vinegar, the remaining 1 teaspoon of sesame oil, mirin, soy sauce, wasabi, garlic and ginger.
Step 5Pour over the greens and noodles and toss to coat evenly. Sprinkle the salad with salt and pepper to taste.