Step 1

Preheat the oven to 200C/180C Fan/Gas Place the shallots in a heat-proof bowl, cover with just-boiled water and leave to stand for five minutes. This will make the skins easier to remove.

Step 2

Remove any string from the chicken and place the lemon and bay leaf inside the cavity. Generously season the chicken inside and out with plenty of flaked sea salt and freshly ground black pepper. Sprinkle with the chopped thyme over all sides.

Step 3

Melt the butter with the oil in a large flameproof casserole. Brown the chicken over a medium-high heat for a couple of minutes on each side.

Step 4

Drain the shallots and, once cool enough to handle, peel off the skin and trim, halving any larger ones. Add the whole garlic cloves and shallots to the casserole, nestling around the chicken.

Step 5

Pour over the vermouth and chicken stock. Cover the casserole with a tight-fitting lid and bring the liquid to a simmer on the hob, then transfer to the oven for 1¼ hours, or until the chicken is thoroughly cooked and the garlic is completely softened.

Step 6

Transfer the chicken, garlic and shallots to a warmed platter and cover with a piece of foil and a couple of dry tea towels. Holding the casserole with an oven-cloth, tilt the chicken liquor to one side. Skim off any fat that rises to the surface and discard.

Step 7

Return the casserole to the hob and stir in the tarragon and cream (or crème fraîche). Bring to a gentle simmer, stirring. Cook for three minutes. Season to taste and pour into a warmed jug.

Step 8

For the colcannon, peel the potatoes and cut into evenly-sized chunks. Put in a large saucepan and cover with cold water. Bring to the boil and cook for about 15 minutes, or until very tender. Test with the tip of a knife.

Step 9

While the potatoes are cooking, trim the thick stems and cut out much of the tough central vein from each kale leaf. Thinly shred the leaves and wash in a colander under cold running water. Drain.

Step 10

Heat 25g/1oz of the butter in a large non-stick frying pan and fry the bacon and kale for four minutes, stirring regularly until the kale is tender. If it is still a little tough after four minutes, add a couple of tablespoons of cold water and continue cooking for a couple of minutes more. Add the spring onions and cook for one minute, stirring.

Step 11

Drain the potatoes in a large colander and return to the saucepan. Leave to stand for a couple of minutes. Warm the cream and remaining butter in small pan. Mash the cooked potatoes with the cream and milk until smooth and season to taste. Use a set of electric beaters if you want your mash to be really fluffy and light.

Step 12

Tip the softened kale into the same pan and stir together until lightly combined. Transfer to a warmed dish.

Step 13

Carve the chicken into chunky pieces and serve with the sauce and colcannon. Squeeze the garlic out of its skin and spread on the bread just like butter.