Heat oven to 190C/170C fan/gas 5.
Put the pancetta in a heavy-based frying
pan and gently fry until crisp – if you start
the pancetta slowly from a cold pan you
shouldn’t need to add oil. Lift out with a
slotted spoon and set aside. Add shallots
to the pan, there should be some pancetta
fat left, then fry for 10-15 mins until
golden and starting to soften. Tip the
shallots into your largest roasting tin.
Rub the olive oil over both chickens,
season well with salt and pepper, then
snuggle the chickens into the tin. Roast
for 1 hr 20 mins until golden and cooked
through. To check they’re cooked, pierce
the thighs through to the bone – the
juices should run clear. Lift the chickens
onto a plate or another tin, cover with foil
and rest while you finish the veg.
Put the roasting tin directly on the hob
and stir in the stock. Bubble for a few
mins, scraping up any stuck bits, then stir
in the peas, pancetta and most of the
chopped tarragon. Bubble for a few mins
more until the peas are cooked, then
season and sit the chickens back on top,
or transfer everything to a serving dish if
you want a smarter presentation. Scatter
the chickens with the remaining tarragon,
and serve with potatoes – mashed, jacket
or roasted, or boiled new potatoes.