Preheat the oven to 170°C/340°F/gas mark 3½.

Season the chicken inside and out.

Remove any discoloured outer leaves from the lettuces and trim the root ends.

Heat the butter and oil in a reasonably heavy-based, ovenproof saucepan or casserole in which the chicken can sit snugly surrounded by the lettuces.

It needs to have a lid.

Brown the chicken all over – carefully turning it so you don’t rip the skin – then pour in the wine and add the thyme.

Bring to the boil then immediately reduce the heat, cover and put into the oven.

Cook for 1½ hours, taking the lid off after 50 minutes and tucking the baby gems in round the bird.

Baste them with the cooking juices to make sure they are well moistened.

Brown the lardons in a small frying pan in their own fat – it will just start to run out when you heat them – and scatter them over the top of the lettuces.

Return to the oven without the lid.

Continue to cook, basting the lettuces and turning them every so often.

The chicken is cooked when – if you pierce between the legs and the rest of the body with the tip of a sharp knife – the juices run clear with no trace of pink.

Take the chicken and the lettuces out of the pot (be careful with the lettuces as they are delicate), put on a warmed platter, cover with foil and insulate (I use old tea towels for this).

Remove the thyme and strain out the bacon (reserve it).

Pour the cooking juices into a jug, skim the fat from the top and discard it.

Heat the cooking juices and add the cream.

Boil until you have a sauce about the thickness of single cream, then add the parsley and reserved bacon.

Add a squeeze of lemon juice (this will thicken the sauce) and taste for seasoning.

Serve the chicken on a platter surrounded by the lettuce with the creamy parsley sauce on the side.