Mix all dressing ingredients except sesame seeds and spring onions in a bowl.
Pour 2 tablespoons of dressing over the meat and allow to marinate for a few minutes.
Cook soba noodles in boiling water for approx. 8 mins or as directed on packet. In last 3 minutes of cooking time add beans to blanch using a wire sieve for easy separation.
Cook beef in hot pan with a dash of peanut oil, about 3 minutes each side. Rest and slice.
Serve in bowl with noodles, beans and top with thinly sliced beef.
Add sesame seeds to the dressing. Dress the dish generously with the dressing and top with crispy shallots.