Green chicken salad

• 1 small red onion
  finely chopped
• 1 lemon
  juiced
• 1 small rotisserie chicken
  around 250g meat, picked and shredded
• 4 sticks celery
  finely chopped
• 4 spring onions
  finely sliced
• ½ large cucumber
  deseeded and finely chopped
• 6 cornichons
  roughly chopped
• 1 green pepper
  deseeded and cut into 1/2cm cubes
• large handful of soft herbs
  (we used dill and parsley), roughly chopped
• toasted sourdough
  to serve

For the dressing

• 50g natural yogurt
• 2 tsp Dijon mustard
• 50g mayonnaise
• 50ml olive oil