Preheat oven to 425 F
Remove the giblets from the chicken cavity. Rinse the chicken then pat dry (inside and out).
Stuff one onion and both halves of garlic into the chicken cavity with 3/4 of the thyme and rosemary. Tie the legs with kitchen string and tuck the wings.
Chop the remaining thyme and rosemary and place in a bowl with the Hellmann's Mayonnaise, salt and black pepper. Mix to combine.
Spread 1/4 of the mayonnaise mixture over the entire chicken and toss the remaining mixture with the veggies, stirring to coat.
Place the chicken in a roasting pan with the veggies and bake for 1 hour, or until juices run clear.
Slice the chicken and serve with the roasted vegetables.