Baby greens with chicken and spring vegetables

Ingredients

• 1 tbsp olive oil
• 2 skinless, boneless chicken breasts , sliced 1/4 in thick
• 1/2 bunch asparagus , trimmed, about 160 g
• 8 cups baby romaine lettuce
• 1 cup watercress
• 1/2 cup radishes , trimmed and halved
• 1/2 cup red grapes , halved
• 16 mini bocconcini

FOR HONEY DIJON DRESSING:

• 2 tbsp olive oil
• 2 tbsp white-wine vinegar
• 2 tbsp finely chopped fresh tarragon , or 2 tsp dried
• 2 tsp honey
• 1 tsp Dijon mustard