Preheat oven to 180°C.
To make the stuffing, heat the oil in a frying pan over medium-high heat.
Add the mushroom, bacon and leek and cook, stirring, for 5 minutes or until the bacon and mushroom is golden.
Transfer to a heatproof bowl.
Add the breadcrumbs, thyme, egg and KNORR Roast Chicken Gravy powder, and stir until combined.
Loosely fill the chicken cavity with the stuffing.
Place chicken in a roasting pan and drizzle a little oil over it.
Season with salt and pepper.
Sprinkle with thyme.
Roast chicken for 1 ½ hours at 180°C, until succulent and golden brown.