Creamy Mustard Chicken on Mash

Name: Creamy Mustard Chicken with Fine Beans
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Ingredients: 4 chicken breast; 900 g white potatoes; 2 leek (prepped); 400 g fine beans (stalk trimmed); 30 ml olive oil; 1 knob butter; 30 ml milk; 200 ml chicken stock (use stock cube); 150 g soured cream; 1.5 tbsp wholegrain mustard (or Dijon)