Preheat the oven Gas 5, 190°C, 375°F. Put the chicken in a roasting tray. Smear the butter all over and season well. Put a large sprig of the tarragon and the thyme into the cavity and pour the wine around, adding a splash of water as well.
Roast for 30mins, then add the whole shallots, bacon and garlic to the tin. Roast for another 40mins, adding a splash more water if the juices in the roasting tray dry up. Lift the chicken with some tongs so the juices run from the cavity. The chicken is cooked if the juices are clear - if they're still slightly pink, cook for a further 10mins.
Stir the peas into the juices around the bird and scatter with some fresh tarragon. Allow to sit for 10mins, then remove from the roasting tin and carve.
Reduce the juices a little to make some gravy and serve with new potatoes and vegetables or salad.
Top tip
If you've got leftover chicken, turn it into a tasty and quick chicken salad. Shred the meat and toss it together with boiled baby new potatoes and mixed salad leaves. Just before serving, dress it with extra virgin olive oil and lemon juice or balsamic vinegar.