By now, the water should have boiled, add the soba noodles and cook according to the package directions.
While the noodles are cooking, grab the remaining dressing base, add the peanut butter and wasabi paste and whisk to combine. If the peanut butter is being a pain and not incorporating fully (like mine was,) just microwave the dressing for about 20-30 seconds until the mixture is smooth.
Once the noodles are cooked, drain them in a colander, and rinse under cold water until completely cool. Leave them to drain in the colander while you cook the steak.
Set a cast iron pan over medium high heat, and heat until very hot, Add the steak and cook for about 5-6 minutes on the first side, until browned and the sides of the steak are looking cooked. Flip and cook another 4-5 minutes or until cooked to your liking. I like mine pretty rare.
Remove to a board to rest for a moment.
Now pour the cooled and drained noodles into a large serving dish, add the sliced peppers and edamame beans. Toss with the dressing (you may not need all the dressing, use your discretion) and sprinkle the top with the chives and about half the black sesame seeds.
Slice up the steak and add it right to the top of the salad. Sprinkle with the remaining sesame seeds.
Serve immediately or put in the fridge for a super cold salad a little later.