Chicken with chilled noodles, cucumber and Sichuan-vinegar dressing

Name: Chicken with chilled noodles, cucumber and Sichuan-vinegar dressing
Cuisine: Asian
Ingredients: 500 ml chicken stock (2 cups); 6 spring onions, white parts thinly sliced, green tops reserved; 3 garlic cloves, crushed; 1 long red chilli, split; 2 thin slices ginger; 2 chicken breasts (about 160gm each); 180 gm soba noodles; 1½ tsp sesame oil; 150 gm podded frozen edamame; 1 tbsp roasted black sesame seeds; 1 tbsp roasted white sesame seeds; 2 Lebanese cucumbers, seeds removed, cut into long, thin julienne; 1 cup coriander, coarsely chopped; Black vinegar dressing; 2 tbsp black vinegar; 2 tbsp soy sauce; ½ tbsp Sichuan peppercorns, toasted and crushed; 2 tsp caster sugar