Wash and dry the chicken, sprinkle it with a bit of lemon juice and season to taste. Put in the belly of the chicken the sprig of thyme and place it in a large pan.
Peel the potatoes, cut them into large pieces, season to taste and put them in the pan around the chicken. Pour over the olive oil, thyme and the remaining lemon juice, cover the pan with foil and place it in the oven.
Bake the chicken in a moderate oven for at least 1 hour and when it is nearly done, remove the foil so that the food turns golden brown. If it's necessary, during baking you can add a little water.