Place all of the brine ingredients into a large saucepan. Cover with a lid and boil for one minute, stirring to dissolve the salt. Remove from the heat and set aside to cool.
Rinse the chickens thoroughly under cold running water. Add the chicken to the brine. (Ensure it’s submerged in the brine – you can do this with a plate, if necessary.) Chill in the fridge for six hours.
Preheat the oven to 240C/475°F/Gas 9.
Remove the chickens from the brine, rinse under cold running water and pat dry with kitchen paper.
Season the inside of each chicken with a light sprinkling of salt and freshly ground black pepper.
To truss the chickens, place one chicken on a tray with the legs towards you. Tuck the wing tips under the bird. Cut a 90cm/3ft piece of kitchen twine and place it on top of the neck end of the breast.
Lift the neck end of the bird and pull the twine down around the wings and under the chicken, then bring the ends up over the breast, towards you, and tie the twine into a knot, pulling it tight to plump the breast.
Bring the ends of the twine around the ends of the drumsticks and straight up. Tie as before to pull the drumsticks together and form a compact bird; tie again to secure the knot. Repeat the process with the second chicken. Let the chickens sit at room temperature for 20 to 30 minutes before roasting.
Season the outside of the chickens with a light sprinkling of salt and freshly ground black pepper.
Place two heavy-based, ovenproof frying pans over a high heat. When they are hot, add half the oil to each and heat until hot.
Put the chickens breast-side up into the pans, and then into the oven with the legs facing the back of the oven. Roast for 40 minutes, checking the birds every 15 minutes and rotating the griddle pans if the chickens are browning unevenly.
After 40 minutes, check the temperature of the birds by inserting a thermometer between the leg and the thigh. The temperature should read approximately 68C/155F. (The chicken will continue to cook as it sits, reaching a temperature of about 73C/165°F.)
When the birds are cooked, remove from the oven, add the thyme leaves to the pans, and baste the birds with the juices and thyme leaves. Set aside in a warm place for ten minutes.
To carve the chicken, cut the twine between the legs and pull on one end; the entire piece will pull away easily. Cut each bird into four pieces.
Remove each leg by cutting through the joint where the thigh joins the body. Slice off each side of the breast, leaving the wings attached to the breast meat; cut off and discard the wing tips.
For the chasseur jus, place the canola oil into a saucepan over a medium heat. Add the shallots, carrots, garlic cloves and button mushrooms. Fry until lightly coloured.
Add the tomato and stir until well combined. Pour in the wine and reduce the sauce until the liquid has almost evaporated.
Add the herbs and chicken stock. Bring to a simmer and skin the scum regularly for 30 minutes. Strain the sauce through a fine sieve and into a clean saucepan.
For the waffles, preheat a waffle maker to a medium setting and preheat the oven to 140C/275F/Gas 1. Place a large wire rack onto a baking sheet and keep it warm.
Mix the flour, baking powder, salt and granulated sugar in a large mixing bowl. Whisk in the eggs, milk and butter until well combined.
Ladle some of the batter into each well of the waffle maker and close the lid and cook for five minutes, or until golden-brown and crispy. Repeat the process until the batter is used up.
To serve, arrange one piece of breast and a leg on each serving plate and top with the sauce. Sprinkle with fleur de sel and place two waffles alongside. Serve with vanilla butter and maple syrup.