Preheat the oven to 500° F.
Wash the chicken and pat dry. Discard the giblets. Squeeze the lemon quartered inside the chicken cavity. Place 2 of the quarters in the very back of the cavity, followed by the thyme. Lay the garlic cloves on top of the thyme, sprinkle with pepper, and add the remaining lemon quarters.
Place the chicken on its back in a roasting pan. Melt the butter in a saucepan. Remove from the heat, and stir in the vermouth. Drizzle half the mixture over the chicken. Bake 20 minutes.
Remove the chicken from the oven. Using a flat spatula and a carving fork, turn the chicken over onto its breast. Return to the oven for 20 minutes.
Remove the chicken from the oven and turn it over, breast side up. Drizzle the remaining basting sauce on top. Roast until dark golden brown all over, about 20 minutes.
Remove the chicken from the pan and transfer to a carving board. Let rest 10 minutes before slicing. Serves 4 (or 1 person 4 times all week long).
Makes: 4