Pre-heat the oven to 160c
Get all of the veg prepared, and the stock made up
Fry the onion in a large casserole dish for about 5 minutes until softened
Add in the garlic, rosemary sprigs and chicken thigh fillets, and stir fry for another 5 minutes
Stir the cornflour through everything that is frying, and then pour in the chicken stock
Add the carrots, potatoes, dried thyme, dried parsley and season with salt & pepper
Pop the lid on and put into the oven (middle shelf) for an hour
When the casserole comes out of the oven, sprinkle the finely chopped fresh parsley over the top and serve!
