Marinate the chicken thigh fillets. Set aside. Pre-heat the oven to 190C/ 170Cfan/ gas 5.
Heat the oil in a large ovenproof casserole. Add the onion and bacon lardons and cook over a medium low heat until the onion has softened. Increase the heat and add chicken pieces and cook for 2-3 minutes. Add the garlic and cook for 1 min.
Deglaze the pot with chicken stock, scrapping the brown bits stuck at the bottom.Add all the vegetables and to the casserole. Bring to simmer and cook for 5 minutes.
Top with potato slices, over lapping a little for each slice, covering the entire surface, brush with melted butter. Place in oven and cook for 45- 50 minutes, till potatoes turn golden brown. Garnish with parsley.