Remove any giblets from chicken (if they came with chicken). Wash chicken inside and out and pat dry. Place chicken on a rack in roasting pan.
Separate cloves of garlic from bulb - leaving paper covers on cloves. Stuff cavity of chicken with all 40 cloves - all the way to the neck - and truss chicken legs together so garlic will not come out.
Spray chicken all over with a good coating of cooking spray. Sprinkle chicken with Kosher salt and freshly ground pepper.
Place chicken in 375 degree oven and roast for 1 hour and 45 minutes. While chicken is cooking, cut French bread in half lengthwise and toast.
Once chicken is done, remove all garlic cloves before carving. Open several cloves from their wrapping and rub along the two halves of toasted French bread. Top bread with salt and pepper.