Preheat the oven 190°C.
Put the chicken in a roasting tray, then rub the butter all over and under the skin (loosen the skin at neck). Season with salt and pepper (including inside the cavity).
Put 2 sprigs of the tarragon and the thyme into the cavity. Pour the wine around the bird. Roast for 30 minutes.
Meanwhile cut the onions into wedges and the bigger peppers into large chunks. Squash the garlic a little bit. Add these to the tin together with the bacon, then roast for another 30 minutes, basting the chicken a couple of times. Add some water if it's getting dry.
Add the peas or broad beans and the remaining tarragon to the tray. Cook for another ten minutes.
Remove the chicken from the tin, allowing the juices to run from the cavity. Check (at the thighs) if the chicken is cooked through - if the flesh is slightly pink and/or the juices are pink, cook for a few more minutes.
Transfer the chicken, bacon and vegetables to a serving plate, cover and let them rest.
While the chicken is resting, make some gravy by reducing the juices on the hob.
Carve the chicken and serve it with the vegetables and other side dishes of your choice.