Pre- heat the oven to 300°F.
Remove the chicken from the brine and pat dry with paper towels. Season the chicken inside and out with salt and freshly ground pepper. Stuff the cavity with the lightly crushed garlic, lemon quarters and basil and tarragon, setting aside a few leaves of each for the bread salad.
Place the chicken in a large roasting pan, breast-side up, with the wings tucked under its back, and truss the legs together to close the cavity. Roast at 300°F for 1 hour, until both the thigh and the breast read 150°F with a meat thermometer. Remove the chicken from the oven and increase the oven temperature to 400°F. Thoroughly brush the chicken with 2 tablespoons olive oil, then return to the oven and bake until crispy and golden brown, 10-15 minutes. Remove the chicken from the oven and set aside to rest while you prepare the bread salad.
Heat 1 tablespoon olive oil in a large frying pan over medium-high heat and add the bread. Sauté until crispy and golden. Once it’s golden, grate 1 clove garlic with a microplane and toss with the bread over the heat for 20 more seconds. Remove to a large bowl. Add the shallots and tomatoes to the bread; drizzle with the remaining 4 tablespoons olive oil, the sherry vinegar and a few torn leaves of basil and tarragon and set aside.
Arrange the bread salad around the chicken in the roasting pan and serve.