Prepare your vegetables and chicken for the stew first. Potatoes should be halved or quartered. Green beans can be snapped in half, or can remain whole.
Baby carrots can be kept whole if desired. Fennel should be finely sliced. Leaves should be picked from the sprigs of thyme. Rainbow chard is to be sliced into large strips. Parsley should be roughly chopped.
Chicken should be diced into small chunks.
Heat the olive oil in a medium sized casserole at a low temp for five minutes. Add the fennel and thyme and allow them to sweat for five minutes.
Add chicken, potatoes, and carrots, as well as all desired seasonings.
Add the chicken stock and the mustard, and cover the dish. Cook on medium for 30 minutes.
Uncover the dish after 30 minutes, adding the rainbow chard and green beans. Allow to cook for 5 more minutes.
Season the dish to taste using the remaining seasonings. Serve with a squeeze of lemon juice and freshly chopped parsley.